An operational issue west of Union Station that resulted in lengthy delays for many commuters Wednesday has been resolved.

Metrolinx, the Crown agency responsible for GO Transit, said a train experienced a mechanical issue at 4:25 p.m. just as it pulled out of the downtown Toronto station.

"The issue has been resolved  and the train cleared from the tracks. However, because the train was blocking incoming and outgoing trains, delays resulted on our lines," a spokesperson said in an emailed statement.

"We are still experiening residual delays and encourage people to check the GO website for updates."

In posts shared to X, formerly Twitter, commuters can be seen standing shoulder-to-shoulder waiting on train platforms at the downtown Toronto station.