The first images of the Thai boys since their rescue from the cave have emerged.

The first video of the Thai boys rescued from a flooded cave after 17 days shows them smiling and waving from their hospital beds, looking thin but fine after an ordeal that has gripped the world.

The last group of the 12-member “Wild Boars” soccer team and their coach was brought out of the Tham Luang cave, near the border with Myanmar, on Tuesday night, safely ending a dangerous rescue and evoking international relief and joy.

Rescue mission chief Narongsak Osottanakorn told a news conference the boys were just being children when they got lost and no one was to blame.

“We don’t see the children as at fault or as heroes. They are children being children, it was an accident,” Narongsak said on Wednesday.

A video of the boys in hospital was shown at the news conference. Some of them, wearing surgical masks, lay on their beds. Some sat and made the peace sign for the camera.

#WATCH First video of the boys who were rescued from Tham Luang cave complex yesterday, in hospital (Source: Thai government) pic.twitter.com/xCqPuT6AOt

— ANI (@ANI) July 11, 2018

The 12 boys and their soccer coach lost an average of 2kg during their ordeal but were generally in good condition and showed no signs of stress, a senior health official said earlier.

After being brought out of the cave, one by one beginning on Sunday, they were taken by helicopter to hospital in the town of Chiang Rai, about 70km away, to stay in quarantine.

The boys would have to stay in hospital for up to 10 days, hospital director Chaiwetch Thanapaisal told the news conference. They would then need to recuperate at home for 30 days, he said.

Parents of the first eight boys freed have been able to visit them but had to wear protective suits and stand two metres away as a precaution. Authorities are worried about the possibility of infections picked up in the cave.

Thongchai Lertwilairattanapong, a health department inspector, earlier told reporters one from the last group rescued on Tuesday had a lung infection and they were all given vaccinations for rabies and tetanus.

The group ventured into the vast cave complex in the northern province of Chiang Rai after soccer practice on June 23 and were trapped when a rainy season downpour flooded tunnels.

They were lost for nine days before British rescue divers discovered them on July 2, sitting on a ledge in a half-flooded chamber.

Getting them out - which involved teaching boys as young as 11 who were not strong swimmers to dive through narrow, submerged passages - proved a monumental challenge.

A former member of Thailand's navy SEAL unit died during a mission in the cave on Friday.

Narongsak, giving details of the rescue, said falling oxygen levels inside the cave complex had added a sense of urgency.

The commander of the navy SEAL unit that oversaw the rescue, Rear Admiral Apakorn Yuukongkaew, hailed the international effort.

"We are not heroes. This mission was successful because of co-operation from everyone," he said. "For SEALs, this is what we were trained for. The navy has a motto: 'We don't abandon the people'."

Official help came from Australia, Britain, the United States, Japan, Laos, Myanmar and China, a government document showed. There were volunteers from Denmark, Germany, Belgium, Canada, Ukraine and Finland.