A warning sign posted in a SkyTrain station warns about pickpockets. (CBC)

Vancouver transit police have launched a campaign to warn transit commuters about pickpockets who could be working the crowds in the city during the Olympics.

Some of the thieves could be coming from elsewhere in the world to take advantage of the flood of tourists, according to Sgt. Tom Seaman.

'They will pick that person who is not necessarily aware of their surroundings'—security consultant Norm Bettencourt

"There may be the local ones that may look for the opportunity, and there may be others from other locations," Seaman told CBC News on Wednesday.

"Whether they are going to come all the way to Canada, I don't know. But we are wanting to make people aware there is a possibility of that and to protect your belongings."

Posters are up on SkyTrain and Canada Line routes warning that, "The World's Best Pick Pockets are Coming to Vancouver."

Officers would also be handing out warning cards to help riders keep their possessions safe, Seaman said.

Practical advice

"They choose the victim," said Norm Bettencourt, owner of TACT Self-Defence in Vancouver.

"They will scan that person first and see if they are not paying attention and they will pick that person who is not necessarily aware of their surroundings."

Bettencourt outlined some simple precautions to help avoid becoming a victim.

• Keep all the zippers closed in jackets and purses.
• Put wallets in a front pocket.
• Pay special attention when people bump into you or spill things on you.