Vancouver police are concerned that one of the city's worst ever shootings could trigger an escalating gang conflict.

Eight people were shot when a pair of masked gunmen opened fire inside a Chinese restaurant early Thursday. Two males died, aged 19 and 26, and police said they both had gang connections.

"We are very concerned about a retaliation," Deputy Chief Doug Le Pard told a press conference Friday.

Witnesses say there was an earlier fight at the same restaurant between a group of Asians and a gang of Indo-Canadians calling themselves the Independent Soldiers. But that hasn't been confirmed by police.

Of the six wounded, police said three were male and three female. Earlier reports had said four were female. But another member of the group -- there were nine in total sitting at the restaurant -- escaped unharmed.

A 26-year-old male is in critical condition, while another male, 22, and female, 19, are in serious condition. The other victims -- another 19-year-old female, a 25-year-old male and 18-year-old female -- are in stable condition.

"We are launching probably one of the largest investigations in our history," said Police Chief Jamie Graham. "We have many officers working on this case."

Police said there are several gangs in Vancouver and some officers are now focusing on keeping peace between them.

"We have our specialty members -- like in our gang crime unit and our criminal investigation section -- who are very much focused on doing what they can to diffuse any tensions that are out there, and gather the intelligence so that we can move on this investigation as quickly as we can," said Le Pard.

When the gunmen opened fire, all nine people were seated at the same table inside the Fortune Happiness restaurant. Police said the establishment is not a known hotspot for gangs.

The shooters fled and police have not identified any suspects.

Graham said the public should not be concerned about any possible retaliatory gang violence. In Toronto, such violence has claimed the lives of innocent bystanders.

"We have some very talented people out there who are doing everything they can to assure the public is safe, they will do their very best to find these offenders," he said.

"We have sources, we have contacts in various elements in Vancouver that our people are going to be beating the bushes to determine that kind of intelligence."

With a report from CTV British Columbia's Dave Lefebvre and files from The Canadian Press