SINGAPORE - Delays over seven hours on the East-West Line (EWL) on Wednesday (Sept 19) were caused by a switch mechanism problem, said Senior Minister of State for Transport Janil Puthucheary.

Thousands of MRT commuters faced delays of up to 40 minutes during the rush hour on Wednesday morning, the second disruption on the line in two days.

"We could have taken a decision to stop service and allow us to just simply concentrate on repairing the problem but that would have been a very big impact on the commuter experience," he told reporters on the sidelines of the launch of the SG Mobility Gallery on Wednesday.

"So the decision we took now allows trains to pass, but it's slowing down the commute. So it's slowing, rather than stopping," added Dr Janil.

"We thought on balance, that was better for the commuters but it does mean that it's going to take a little bit of time to ascertain exactly what the problem is with the switch mechanism."

Dr Janil was speaking to reporters before SMRT tweeted about the rectification of the train fault at 1.35pm.

In a Facebook post at 8.45am, SMRT said that train service had to be stopped between Clementi and Jurong East MRT stations to allow its technicians to go onto the track to check on the fault, which occurred at about 7am.

"Trains are progressively returning to normal speed. Do continue to add 15 minutes of train travel time between Boon Lay and Queenstown," SMRT said at 1.35pm.

At 1.50pm, SMRT tweeted that train services were back to normal.