Bus operator SMRT has released new figures on the number of its bus drivers from China who were involved in the illegal strike.

In a statement just in, SMRT said 171 drivers - not the 102 earlier reported - did not report for work on Monday.

On Tuesday, 88 - 68 from the morning shift and 20 from the afternoon - did not show up. The figure given earlier was 60.

The operator said it takes a serious view of the service delays caused by the "irresponsible behaviour".

It has lodged a police report "for further investigation into possible breaches of the law", and is conducting its own investigations on whether employment terms have been breached.

It also gave the assurance to drivers who were not involved in the strike that the company continues to value their services.