SINGAPORE - Train service on the North-South line faced delays for a fourth day running on Friday (June 30) morning.

SMRT first alerted commuters to a 10-minute delay from Woodlands to Ang Mo Kio stations at 6.32am on its Twitter feed.

The delay extended to 15 minutes about half an hour later, and reduced to 10 minutes again at 7.57am.

The fault was cleared and trains were running normally about two hours later, SMRT said at 8.48am.

The disruption was due to a track fault at Ang Mo Kio station, the tweet said.

The platform towards Marina South Pier at Ang Mo Kio station was crowded but orderly at about 8am. Trains were packed so some in the queue had to wait for the next train.

By about 8.15am, the trains were less crowded and were arriving within a minute.

Beauty consultant Kyrese Foo, 35, said that she was on the circle line and switching to the N-S Line. She said that she was going to be late due to the train delay.

Commuters had faced delays on Thursday morning and Wednesday evening during peak hours.

Accounts officer Eka Airy, 26, was not affected on Friday as it was her day off, but she was delayed for an hour on Tuesday evening.

She left about 30 minutes earlier the next morning for work and got to work on time although there was another train delay.

"Because I left early I got into work on time," she said.

While Wednesday's delay was due to the testing of a new signalling system, Thursday's delays were caused by two separate incidents.

At 6.40am a train encountered a signalling fault at Woodlands, while a faulty platform screen door at Bishan station at 8.20am delayed a train travelling southwards to Marina South Pier.

There were also delays on North-South, East-West lines during morning peak hours on Tuesday.

SMRT had warned of possible delays in the coming weeks as it is testing the new signalling system.