Commuters online spoke of the disruption, with one eyewitness who wanted to be known as Mdm Tan saying that there appeared to be smoke coming from a train arriving at Clementi station at about 9.17am.
Other users on X cited travel delays of between 10 to 20 minutes.
In response to a Facebook comment that said a train was not moving from Kallang to Boon Lay, SMRT said at about 10.10am that westbound trains were being turned around at Queenstown.
“Therefore, train speed is being regulated. We have made in-train and station announcements. We are sorry for affecting your commute.”
The incident on Wednesday is the third train service disruption in slightly over a week.
Service on the Circle Line was disrupted for nearly two hours due to a power fault on the evening of Sep 17, affecting peak-hour travel for scores of commuters.
The next day, a fire at a train depot again disrupted Circle Line services, causing an outage of about 15 minutes.
