Vancouver police are warning visitors to be vigilant after a handful of incidents in which people dressed up like police officers stop tourists, demand to see their passports and wallets, and make off with their cash.

The Vancouver Police Department said six incidents have been reported over the past two days. Police said the phoney officers, who seem to be targeting Asian tourists, even flash fake badges.

"After a few minutes, the passports and wallets were returned to the victims, but their money was missing," the VPD said in a written statement.

All six incidents have taken place in downtown Vancouver in the area near Waterfront Station, police said.

Real police officers should be able to produce police photo identification when requested.

The department is asking anyone with information about the thefts to call 911.

Anyone who doubts the identity of a police officer can also call 911 to have the operator confirm the officer's status, the VPD said.