MIDDLESEX CENTRE, ONT. -- The border crossing in Sarnia, Ont. was shut down temporarily on Thursday morning after the discovery of a suspicious package near the bridge.

U.S. Customs and Border Protection Great Lakes said the Blue Water Bridge closure was due to a suspicious package.

The Port Huron Police Department had to bring in the Michigan State Police Bomb Squad to inspect the package, which was found to be a mechanical device.

The incident shut down all foot, vehicle and boat traffic in the area around the train tracks and scenic turnout north of the Blue Water Bridge where it was found.

OPP had reported a staffing shortage prompted earlier slowdowns at the border crossing.

Traffic on the westbound Highway 402 heading into Sarnia was reportedly extremely slow due to the closure and police were warning drivers to expect delays.