A man and woman have been stabbed with a glass bottle in a suburban food court overnight.

A man is dead and a woman seriously injured after they were attacked whilst dining in a Korean BBQ restaurant on Wednesday night.

The male attacker was allegedly the ex-partner of the woman. Witnesses told Seven News he leaped over the counter and shouted that she’d cheated on him.

The attacker then allegedly stabbed both the man and the woman with a glass bottle.

“He got two in the neck and two in the stomach and he like dropped,” one witness said.

“It was an argument because the guy cheated on his missus for him. The guy was like well, you had my missus.”

Witnesses have said the victims were knocked to the floor before the attacker focused on the male diner.

“He was yelling out ‘help’ and me and my mates we outside, we were freaking out and were like ‘nah, we’ve got to help him’,” a witness said.

“He was laying there and I was like mate calm down you will be all good, just keep calm,”

Witnesses said the offender took off, running through another restaurant next door

Police said emergency services were called to a shopping centre on Florence Street, Hornsby shortly before 9:30 pm on Wednesday.

The man was treated by paramedics at the scene but later died.

The woman suffered stab wounds to her chest, a punctured sternum and lacerations to her forearm.

She has been taken to Royal North Shore Hospital.

It is being reported that a 38-year-old man has been arrested in relation to the crime.

Listen to witnesses share what they saw at the gruesome scene.