4 detained after breaking into Bayview marijuana grow

SAN FRANCISCO (KTVU) - Four people were detained after breaking into a warehouse in the Bayview district at Rankin and Oakdale. 

According to police, there is a marijuana grow operation inside the warehouse. It's not clear if the grow operation is legal or not. 

The suspects pried open a gate and propped it open with a tire as they entered the warehouse. 

The owner of the building saw the break in on surveillance video and called police. 

Police and SWAT blocked off a two block area as they investigated and detained the four suspects. 

It's unclear how much marijuana was in the warehouse.

At this point, additional details have not been released.