MANILA - (3RD UPDATE) Smoke billowed from one of the MRT's trains on Friday, forcing limited operations in the capital's busiest rail line.

Passengers were offloaded near the Cubao station as firefighters sprayed water on the train car.

It was not immediately known what caused the vehicle to emit smoke while on the line's southbound track.

A video shared by Twitter user @iamludo showed the train stalled in front of the Mega Q-Mart market.

Passed by MRT minutes ago and saw this. @ABSCBNNews @ANCALERTS @gmanews @gmanewsbreaking @rapplerdotcom pic.twitter.com/gulPOtuACY

— Ludo (@iamludo) January 26, 2018

Naglalakad sila sa Cubao pic.twitter.com/CgHPjMtcrv

— TJ Manotoc (@tjmanotoc) January 26, 2018

Eyewitnesses told MRT management that they saw smoke coming out from the door of the train car.

Smoke reportedly came from underneath a seat inside the car, where the electronic components were located.

The smoke was contained at 2:15 p.m. and the train was towed for repair, officials said

Twelve trains were running before the incident, but management limited their service from Taft Avenue station to Shaw Boulevard, both in the northbound and southbound tracks, thereafter.