at a depot substation, the transport operator previously said.

On Friday, Mr Sim said that Tuesday's incident had "damaged the back-up switchboard of the power system".

"We are now running on only the main and single switch board. Without the availability of the back-up switchboard, this cable fault caused service to be disrupted and a lengthier service recovery time," he added.

The cable fault also resulted in 10 trains stalling on the tracks, said Mr Sim.

"All passengers, including those on mobility aids, have safely disembarked from the trains. This took some time before recovery works could proceed," he added, apologising for the inconvenience.