Waterloo Regional Police are investigating a bank robbery in Cambridge.

At approximately 7:25 a.m. Thursday, two men entered the TD Canada Trust on the corner of Hespeler Road and Bishop Street in Cambridge.

Both of their bodies were almost entirely covered, as they were wearing hats and gas masks.

Police say the suspects brandished what appeared to be an explosive device and demanded money from the two employees who were preparing for the bank to open.

They then left the bank, leaving the mysterious device behind.

A bomb disposal squad was brought in to investigate the device and determined it to be safe.

Witnesses and the employees were interviewed by police in a nearby business.

“We ask any witnesses to come forward,” said Insp. Daryl Goetz.

“If there was anybody in the Tim Hortons drive-thru line that saw any suspicious vehicles or saw this event take place, we’re asking them to put a call in to our detective unit.”

Police closed Hespeler Road in both directions, between Bishop and Sheldon, as well as the plaza parking lot.

“Because of the time in the morning, most of these businesses weren’t open, so it was a little easier for us to shut it down,” said Goetz.

The road reopened around 11 a.m.

Police say the bank employees were not injured.