10/02/2014 07:10 EDT | Updated 12/02/2014 05:59 EST

OxyContin lookalike pills prompt warning in Surrey, B.C.

Police in Metro Vancouver are asking drug users to be cautious after officers seized thousands of counterfeit OxyContin pills within the past month.

Surrey RCMP Cpl. Bert Paquet said approximately 4,700 of the fake OxyContin tablets, with a street value of possibly $350,000, were found in two locations in Surrey on Sept. 5.

The greenish marbled tablets have "80" stamped on one side and "CDN" on the other, but instead of containing oxycodone, the active ingredient in OxyContin pills, the tablets contain caffeine and fentanyl.

Fentanyl, a powerful, synthetic opiate, is suspected to have caused at least 13 overdose deaths in B.C.'s Lower Mainland in the first four months of 2014, according to the B.C. Coroners Service.

"We know that this prescription drug is a popular choice among recreational drug users,” Paquet said in a written statement. "As a result, we want to warn those users in the community to take the necessary precautions to ensure their safety."

Surrey RCMP says anyone who doesn't feel well after taking drugs, or who sees someone else in medical distress, should call 911 immediately.