'Missing' Canadian teens named as suspects in the murders of Lucas Fowler and Chynna Deese, & more in News in 5.

–With AAP.

1. ‘Missing’ Canadian teens named as suspects in the murders of Lucas Fowler and Chynna Deese.

Kam McLeod and Bryer Schmegelsky are best friends who worked night shifts at a Canadian Walmart together to raise money to go on a working adventure.

On Tuesday, the Royal Canadian Mounted Police named the pair as suspects in a murderous rampage across remote northern British Columbia that included the highway shooting murders of Australian tourist Lucas Fowler and his American girlfriend, Chynna Deese.

McLeod, 19, and Schmegelsky, 18, from Port Alberni, near Vancouver, are also suspects in the death of a yet-to-be identified middle-aged man found lying near where the teenager’s Dodge pickup truck was set alight on Friday.

A massive manhunt is underway, with the teenagers last spotted driving a grey 2011 Toyota RAV4 more than 2000 km away in northern Saskatchewan, a province in central Canada.

The teenage duo is considered so dangerous the RCMP said a decision to call Tuesday's press conference and go public with their concerns was unprecedented.

"If you spot Bryer or Kam, consider them dangerous," said the Royal Canadian Mounted Police's Sergeant Janelle Shoihet.

"Do not approach, do not take action and call 911 immediately."

McLeod and Schmegelsky were originally deemed missing but that has now changed dramatically.

The teens were first loosely connected to the murder of Fowler and Deese on Friday, when their Dodge was found burning on a highway, and a man's body was found 2km away.

That man has not yet been identified, but has been described as Caucasian with a heavy build, 50-60 years old with grey hair and a grey bushy beard.

On Tuesday AEST, police released a composite sketch of a man they believe to be one of the last people to speak to Fowler and Deese on the evening of July 14.

Royal Canadian Mounted Police (RCMP) spokeswoman Corporal Janelle Shoihet said the man - who was described as Caucasian, with darker skin and dark hair with possible beard or glasses - was not a suspect, but a person of interest.

This carnage took place near Dease Lake, 470 km away from the Alaska Highway location near Liard Hot Springs where Fowler and Deese were found shot dead in a ditch.

The distance between the two locations initially had the RCMP reluctant to link the bodies.

McLeod and Schmegelsky, who had been friends since elementary school, had worked to save for a trip north to to find work at Whitehorse in the Yukon Territory. They are now considered armed and dangerous.

"Given these latest developments, Cameron and Bryer are no longer considered missing," Sgt Shoihet said.

"The RCMP are now considering Cam McLeod and Bryer Schmegelsky as suspects in the Dease Lake suspicious death and the double homicide of Lucas Fowler and Chynna Deese."

The RCMP released new, recent security camera photos of the teens in northern Saskatchewan.

Fowler, 23, the son of a senior NSW police officer, and Deese, 24, from North Carolina, were stranded on the highway after their blue 1986 Chevrolet van broke down on the afternoon of July 14.

Fowler and Deese met two years ago backpacking in Croatia, fell in love, and were on a road trip through Canada when they were murdered.

Schmegelsky's family members have offered positive descriptions of the teenagers.

His grandmother, Carol Starkey, told the Times Colonist newspaper Schmegelsky "was a great kid".

His father, Alan Schmegelsky, said his son and McLeod were "best friends who did everything together".

"They even got jobs together at Walmart," Mr Schmegelsky said.

"They were just out on an adventure."

2. 21 charged following a riot at a NSW Central Coast juvenile prison.

Twenty-one people have been charged after a riot at a juvenile justice centre on the NSW Central Coast which lasted more than 20 hours.

The riot broke out at Frank Baxter Juvenile Justice Centre at Kariong on Sunday night.

It's alleged several inmates assaulted each other and then climbed onto the roof of the complex.

Seven people were injured and six were taken to hospital, including an 18-year-old who was initially in a critical condition with stab wounds and facial injuries.

He's now in a serious but stable condition at Gosford Hospital while a 17-year-old and a 20-year-old remain stable.

Nine detainees surrendered on Monday before riot squad officers moved on to the roof about 5.30pm - 21 hours after the riot started - and the remaining 11 detainees surrendered peacefully, NSW Police said.

Five adults and 16 youths have been charged with rioting.

One of the adults faced Gosford Local Court on Monday with his matter next due for mention on August 16.

The remaining four had their matters mentioned in the same court on Tuesday with all due back on August 9.

The 16 youths were expected to appear in Woy Woy Children's Court on Tuesday.

NSW Communities Minister Gareth Ward said the incident was unacceptable and ordered an independent review.

It will be conducted by former assistant police commissioner Lee Shearer and is in addition to plans already in place to establish a unit at the complex to manage high-risk offenders.

"This inquiry will get to the bottom of what happened at Frank Baxter," Mr Ward said in a statement on Monday.

Public Service Association general secretary Stewart Little alleged the group targeted sex offenders within the complex and described the riot as "nothing short of horrific".

He called for a judicial inquiry into the juvenile system, noting it wasn't the first riot at the centre.

Three units at the juvenile justice centre were damaged in the riots and remain part of a police crime scene, a spokesman for the Department of Communities and Justice told AAP.

The loss of the units has meant some of the centre's young inmates have been moved to other complexes.

3. Boris Johnson confirmed as new UK leader.

Boris Johnson, the Brexiteer who has promised to lead Britain out of the European Union with or without a deal by the end of October, will replace Theresa May as prime minister after winning the leadership of the Conservative Party.

His convincing victory catapults the United Kingdom towards a showdown with the EU and towards a constitutional crisis at home, as British MPs have vowed to bring down any government that tries to leave the bloc without a divorce deal.

Johnson, the face of the 2016 Brexit referendum, won the votes of 92,000 members of the Conservative Party, almost twice as many as his rival, Foreign Secretary Jeremy Hunt.

May will leave office on Wednesday after going to Buckingham Palace to see Queen Elizabeth, who will formally appoint Johnson.

"We are going to get Brexit done on October 31, and we are going to take advantage of all the opportunities it will bring in a new spirit of 'can do'," Johnson, 55, said on Tuesday after the result was announced.

"Like some slumbering giant, we are going to rise and ping off the guy-ropes of self-doubt and negativity."

Johnson said the mantra of his leadership campaign had been to "deliver Brexit, unite the country and defeat (opposition Labour leader) Jeremy Corbyn - and that is what we are going to do".

Within less than half an hour, US President Donald Trump had tweeted his congratulations, adding: "He will be great!"

The men have recently been complimentary about each other yet Trump is one of the many leaders, including Russian President Vladimir Putin and Turkish President Tayyip Erdogan, about whom Johnson has previously made derogatory remarks.

In 2015, he accused Trump, then a candidate for office, of "stupefying ignorance" that made him unfit to be president.

An avowed Brexit supporter will now lead the government for the first time since the United Kingdom voted to leave the EU.

At one of the most tumultuous moments in Britain's modern history, it will be now led by a flamboyant figure known for his ambition, untidy blond hair, flowery oratory and cursory command of policy detail.

The 2016 referendum showed a United Kingdom divided about much more than the EU, and fuelled soul-searching about everything from regional secession and immigration to capitalism, the legacy of empire, and modern Britishness.

Johnson has pledged to negotiate a new divorce deal with the EU to secure a smooth transition out of the EU. But if the bloc continues to refuse, he has promised to leave anyway - "do or die" - on the current agreed date of October 31.

Many investors and economists say this would shake global markets and tip the world's fifth-largest economy into recession or even chaos.

The EU said a no-deal Brexit would be a tragedy for both parties but again said the withdrawal deal was not up for negotiation.

"We look forward to working constructively with PM Johnson when he takes office, to facilitate the ratification of the withdrawal agreement and achieve an orderly Brexit," tweeted EU negotiator Michel Barnier.

A Brexit without a divorce deal would also weaken London's position as the leading international financial centre while jolting the northern European economy.

Johnson's Conservatives need the support of 10 MPs from Northern Ireland's Brexit-backing Democratic Unionist Party for even a wafer-thin majority in parliament.

Some Conservative MPs have threatened to topple the government to avert a no-deal Brexit, a step that would probably deepen Britain's crisis and lead to an election.

4. Woman avoids jail following egg attack on Scott Morrison.

A young Victorian woman who tried to egg the prime minister has discouraged others from attacking politicians, stating she's had more attention than she ever wanted "and it's not been great".

Amber Paige Holt on Tuesday avoided a jail term when she was convicted of common assault and handed an 18-month community correction order at Albury Local Court.

Magistrate Rodney Brender ordered the 25-year-old to perform 150 hours of community service and fined her $110 for possessing cannabis at the time of the incident.

Holt pleaded guilty in early July to the common assault charge.

"I don't encourage anyone to follow what I did - it's just caused more drama," she said outside court on Tuesday, adding the attack was "selfish and stupid".

"It's led to a lot of insults, a lot of threats to my family and loved ones, (to) myself. I've had a lot more attention than I've ever had in my life and it's not been great."

The court previously heard Holt put an egg in her pocket before entering the Country Women's Association state conference in Albury in early May.

She planned to break the egg on Prime Minister Scott Morrison's head because she didn't like him "as he was not voted into the position".

But the egg fell from Holt's hand to the ground "and the accused struck the back of the head of the prime minister, jolting his head forward".

The magistrate took into account the circumstances of Holt's actions but, he said on Tuesday, the charge didn't inherently involve a degree of aggravation just because the prime minister was the victim.

Mr Brender noted Holt could have been charged under a similar commonwealth offence that covered more serious attacks on elected public officials.

Nevertheless, he said her common assault was "a more serious example of the offence" and one carried out for political reasons as she wanted to "embarrass" Mr Morrison.

"It was motivated by a dislike of a person she didn't know," the magistrate said.

Holt planned the offence after she heard on radio Mr Morrison was going to be in Albury, the court heard a fortnight ago.

She went to a Coles supermarket to buy eggs specifically to carry out the attack.

Holt on Tuesday said she'd failed in her attempt to focus attention on the plight of refugees on Manus Island "and how we can have a prime minister that can so easily ... organise concentration camps".

5. Man driving a van full of $200 million worth of drugs hits police cars in Sydney.

Police had one of their "easiest" drug busts when a van carrying more than $200 million worth of ice crashed into police cars parked outside a Sydney cop shop.

Detectives say a 26-year-old man was driving the van when it hit two police cars outside Eastwood police station about 10.30am on Monday.

Police stopped the van in the nearby suburb of Ryde where a search uncovered 13 boxes with 273 kilograms of the drug ice, NSW Police said in a statement.

"This would be one of the easiest drug busts NSW Police have ever made," Detective Chief Inspector Glyn Baker told reporters.

"This man has certainly had a very, very bad day. Crashing into a police vehicle with that amount of drugs on board is somewhat unheard of - it's an exceptional set of circumstances."

The drugs have an estimated street value of more than $200 million. Investigators are now working to determine who else may be involved in the syndicate.

"With a haul of this size - this has now initiated quite a significant investigation," Det Chief Insp Baker said.

Police are still trying to determine what caused the man to swerve into the parked cars.

One of the police vehicles - a Holden Commodore - was written off while the other was slightly damaged.

The 26-year-old was charged with supplying a commercial quantity of drugs, negligent driving and not giving his particulars to police.

He was refused bail to appear at Burwood Local Court on Tuesday.