Vancouver police are warning people to be mindful of their smart phones after seeing an increase in violent cell robberies, including some that were committed at gunpoint.

Police said the number of reported phone robberies in the city plummeted for years after the introduction of the international stolen phone blacklist, from 215 in 2012 down to 131 in 2014.

That progress came to a halt last year, however, and the trend appears to be reversing in 2016.

“We’re seeing a rise,” said Const. Brian Montague. “Numerous robberies that involve anything from intimidation to the use of physical force or weapons.”

There were a whopping 40 smart phone robberies in Vancouver from January through March, a spike of roughly 30 per cent over the same period last year.

Montague said the severity of crimes range from snatch-and-grabs to incidents where victims were thrown to the ground or even threatened with a gun or knife.

And Vancouver isn’t alone. Since February, three people who tried to sell iPhone 6s on Craigslist have been pepper-sprayed and robbed by someone who responded to their ads in Abbotsford.

Const. Ian MacDonald said the victims were attacked almost immediately after meeting their assailants.

“Once the suspects get a clean eyeshot of the phone, recognize it's present, they just spray the victim, take the phone and they’re on their way,” MacDonald said.

Thieves target devices that have been reset for re-sale because pricey phones can become worthless if a criminal gets locked out by a password, according to tech expert Mike Agerbo.

“It’s so difficult to crack into an iPhone or Android phone. It’s next to impossible. They want the ones that are factory cleaned so that there’s no passcodes or IDs,” Agerbo said.

Police recommend that victims report thefts to law enforcement and their cellular carrier. The device’s identification number can then be added onto the International Mobile Equipment Identity blacklist, making it worthless.

Anyone buying used phones is also advised to check to see if it’s been reported stolen before handing over any money. To check a phone’s IMEI number, visit the ProtectYourData website.

With a report from CTV Vancouver’s Shannon Paterson