A police bomb squad was called into Vancouver's downtown core overnight to investigate a pressure cooker that was left on Granville Street.

The appliance was discovered at around 9 p.m. on a bench outside the 7-Eleven on Drake Street, triggering a heavy police response that disrupted evening traffic for several hours.

By about midnight, authorities had determined there was no risk to the public.

Though witnesses reported hearing a loud blast, police said it was only a controlled explosion performed by a bomb disposal robot.

"The item was not an explosive device," Const. Jason Doucette told CTV News in an email. "Any noise was from our officers destroying the item in a controlled manner."

Authorities are still working to determine how and why the pressure cooker was left on the busy Granville Strip in the first place.

During the police response, which involved members of the ERT team, northbound bridge traffic was temporarily diverted to Seymour Street, and southbound traffic was diverted to Howe Street.