[UPDATE: on 12 January at 10am, adding comments from SMRT on disruption]
It was "probably a cable fault" that resulted in Saturday's massive train service disruption that affected several stations on the North-South line, said transport operator SMRT.
In brief comments in response to a Facebook post on Saturday afternoon, spokespersons for the company said just after 2:15pm that train service had resumed at 2:05pm, and that its engineers were "still on site conducting investigations".
In a subsequent comment, SMRT said, "SMRT engineers will continue to investigate the cause of the fault, and will rectify the issue after operation hours." It did not elaborate on the exact cause of what it previously described as a "traction power loss" that resulted in the nearly-two-hour disruption.
On Saturday, passengers were detrained at Kranji, and at least one train station was shuttered with commuters being turned away, around lunchtime.
Tweets from SMRT said a "traction power loss between Kranji and Yew Tee" at 12:30pm disrupted train service from Woodlands to Choa Chu Kang stations.
Eyewitnesses who spoke to Yahoo Singapore said commuters were being told to exit stations at both Kranji and Yew Tee, and another reader who visited Marsiling train station at 1:30pm found it completely shuttered, with a banner indicating a disruption in train service.
Crowds of passengers were seen at Yew Tee MRT station, and as late as at 1:20pm, passengers were seen walking on the train tracks a significant distance from Kranji MRT station.
Said one commuter Jinson Xu, who was at Choa Chu Kang slightly before 1pm, "The train (towards Yew Tee) finally moved off after five minutes of waiting. (I) reached Yew Tee and saw hordes of people standing around looking lost until an announcement came about shuttle buses being available outside the station."
He said he then crossed the road to wait at the opposite side instead, noting that although there was a significant crowd, its size was "relatively mild" compared to the one at Bishan MRT during the 2011 evening peak hour disruption.
"The shuttle buses started coming at higher frequencies around 13:30, and dissipated a lot by 13:50 or so," said the 30-year-old IT engineer. "Police were spotted helping SMRT staff do crowd control, such as erecting barriers and directing traffic."
SMRT tweeted that it had sent engineers onto its tracks to investigate and rectify the situation, while activating free shuttle bus services between Woodlands and Yew Tee stations.
Firefighters from the Singapore Civil Defence Force were also photographed walking on the train tracks near Kranji station.
When asked, a spokesperson for the SCDF said they were contacted for assistance at 12:40pm, and had sent a fire engine and one ambulance to Kranji MRT station. He said there were no reported injuries, however, and their assistance was no longer required.
Additional reporting by Nurul Azliah Aripin
Check out pictures of the disruption sent to us by some of our readers on the ground: