Toronto police busted a marijuana grow operation Friday, seizing about 5,000 pot plants at an industrial complex in Scarborough.

Police burst through the doors of 154 Shorting Rd., in the Markham Road and Sheppard Avenue East area, around 8 a.m.

Police estimated the street value of the drugs to be about $5 million. Police told CTV Toronto that some of the marijuana would likely have remained in Toronto while the rest may have been destined for export to cities across the United States.

No one was in the unit at the time of the raid, so police will use information from lease agreements to identify suspects.

During the raid, police also found paraphernalia needed to sustain the pot plants: lights and other equipment to keep the room temperature high.

Several owners from nearby businesses told CTV Toronto they had no idea a marijuana lab was in their midst.

With a report from CTV Toronto's Jim Junkin