Commuters travelling on a Pasir Ris-bound train on the East-West Line during evening rush hour received a wet surprise on Monday.

In a video posted on Facebook by a commuter, water is seen trickling from the ceiling air-conditioning vents, forcing travellers to run for cover.

In response to queries, SMRT's vice-president for corporate information and communications Patrick Nathan said that its operations control centre was alerted to a leak in the air-conditioning system, and staff boarded the train at Commonwealth Station to check the leak and clear up the water.

"The train was subsequently withdrawn from service.

"We apologise to affected commuters," he said.