Two armoured truck guards were injured in an explosion as they were robbed at an Edmonton bank Thursday morning.

Edmonton police say the robbery occurred early Thursday morning at a Scotiabank in the city’s northeast end.

Karan Singh, who works in the area, told CTV Edmonton that he heard two explosions shortly after 2 a.m. local time.

“I just heard a bomb blast … and one of my customers told me ‘Down the street, people are screaming out there,” he said.

According to police, the explosion occurred as the guards entered the lobby of the bank. The guards were then robbed by a disguised suspect who was able to get away on foot with cash.

Police did not have any information about the exact cause of the explosion.

Both guards suffered facial and head injuries that are considered serious, but not life-threatening.

A spokesperson for their employer, GardaWorld, said the guards were “safe and in good hands” following the explosion.

‘We are providing support to our employees, their families and colleagues at the branch,” Isabelle Panelli said in a statement.

A similar incident in September involved a bomb going off in the vestibule of an RBC branch on the other side of Edmonton as security guards arrived. Injuries reported at that time were not serious.