GO train service is slowly returning to the Lakeshore East line after an engine fire stopped a train travelling from Oshawa to Union Station on Monday morning and eventually forced all 200 passengers to disembark.

Firefighters, police and transit safety officers were called to the scene in the Don Yards, near the Distillery District in Toronto's east end around 10:30 a.m.

The car behind the engine was evacuated and passengers waited inside the remaining cars for a second train to pick them up and take them to Union Station, Metrolinx spokesperson Anne Marie Aikins told CBC Toronto.

Emergency crews attend a fire on a GO train near the Distillery District in Toronto on Monday. (Stephen Weir/Twitter)

"We're very relieved our crew responded quickly and appropriately to ensure our customers, residents in the area and our staff are safe," Aikins said.

Fire gave off 'strong stench'

Fire crews were able to put the fire out quickly, Aikins said, adding there's no word on what caused the fire.

"Residents were reporting a very strong stench of electrical burning, which gives off a very distinct stench," she said, adding a full investigation is underway.

About 200 passengers were on the train, but hundreds more were delayed as train service along the line was suspended for a few hours.

A Twitter account for GO Transit on Monday afternoon asked commuters to "please be patient as service will take some time to return to normal."

The evacuated train was taken to Union Station.