It was a rubber conveyor belt that caught fire at the TTC station under construction on Jane near the 407 on Wednesday afternoon.

The call came in to Vaughan Fire around 1:30, on reports heavy black smoke was pouring out of the tunnels.

TTC Spokesperson Brad Ross says they don't know how the conveyor belt caught fire, but it was quickly put out.

He says there were no injuries reported.

The subway extension has been plagued with delays because of incidents while building the stations. A man was killed on the construction site at York University, which pushed the completion back a number of months.

Ross says, as it stands the completion date remains at mid 2016, but he couldn't say what this firs would do to their schedule.

He admitted it could be negligible, and that it could have been lots of smoke, making it look bad.

He won't be able to say for sure, until investigators have a good look at it.