Commuter train service on the Saint-Jérôme line is back up and running after all trains were cancelled during the morning rush hour.

A piece of Canadian Pacific equipment derailed during maintenance on a segment of the rail where there is only one track, so it blocked the trains, said Caroline Julie Fortin, spokesperson for exo, the organization that oversees train, bus and paratransit service in the Greater Montreal area.

"We could not have planned this. We're doing our very best to make sure users have alternatives to use to get to work, but of course we recommend people leave home a little bit earlier, plan their itineraries differently and see what their options are," said Fortin.

The service resumed around 11 a.m.

Train fares were accepted on buses and at Metro stations that service train stations along the line.

Service on the other lines was not affected. Trains on the Vaudreuil-Hudson, Saint-Jérôme and Candiac lines all run on tracks that CP leases to the transit authority.