A gunman killed two people and wounded two others in a series of shootings near Vancouver in the early hours of Monday, before being shot dead by police, authorities said. 

Earlier reports had suggested the assailant may have targeted homeless people, but this was not immediately confirmed by authorities in Langley, a town of 130,000 people about an hour southeast of Vancouver.

"I can confirm that four people were shot by what is believed to be a lone gunman," Langley police chief Ghalib Bhayani told a news conference. Two of the victims died, while a third -- a woman -- remained in critical condition, and a fourth person was shot in the leg.

Bhayani said authorities were still working to identify the victims and suspect, and to establish whether there was any connection between them.

"Right now we're determining the exact nature of who these people are and we aren't able to confirm that they are in fact homeless," homicide investigator David Lee said of the victims.

Several Langley residents tweeted images of emergency alerts they received from police at about 6:15 am local time (1315 GMT) confirming "multiple shooting scenes" in the city's downtown area.

A subsequent alert informed residents that the suspect was no longer a threat, but urged them to keep away from the area.

Firearms-related violent crimes account for less than three percent of all violent crimes in Canada -- but since 2009 the per capita rate of guns being fired with intent to kill or wound has increased five-fold.

Following a wave of mass shootings in the neighboring United States, Prime Minister Justin Trudeau has announced a proposed freeze on handgun ownership that would effectively ban their importation and sale.

Canada banned 1,500 types of military-grade or assault-style firearms in May 2020, days after the country's worst mass shooting left 23 dead in rural Nova Scotia.