Some homes have been evacuated in Point-St-Charles after an explosion was heard inside a mail delivery truck Wednesday afternoon.

Montreal police spokesperson Const. Benoit Boiselle said a 911 call came in around 3:30 p.m. about the incident on Ropery St. at Chateauguay St. A Canada Post employee was doing a delivery and when he returned, he heard the explosion.

There were no injuries and there was no visible damage to the outside of the truck.

Police established a large perimeter from Charlevoix St. to de Laprairie St. and from Grand Trunk St. to Centre St.

A special task force from the Montreal police opened the delivery truck and didn’t find any suspicious packages. They were planning to open all the parcels inside the truck.

“For now nothing can explain what caused the explosion,” said Boiselle.

Police are investigating.