OTTAWA - A mechanical issue on a train at St. Laurent station created delays for thousands of riders Thursday night.

OC Transpo tweeted at 4:22 p.m., customers may experience delays due a stopped train at St. Lauren station.

Replacement service was then implemented between St. Lauent and Blair station in both directions. OC Transpo tweeted customers may experience delays of up to 15 minutes at stations west of St. Laurent.

A tweet from OC Transpo 10 minutes later said trains were back running in both directions.

Riders were reporting high volumes of passengers at a number of stations, with major crowding on platforms, as well as on trains.