SINGAPORE - The National Transport Workers' Union (NTWU) on Monday submitted an appeal to rail operator SMRT, against the dismissal of two workers who had been involved in a fatal track accident earlier this year.

Train driver Rahmat Mohd, 49, along with another SMRT employee - who has not been identified - were sacked over the incident in March (2016) which saw the death of two trainee staff.

NTWU's executive secretary Melvin Yong said the union has reviewed the cases, and it has "raised further queries relating to the incident" in its appeal to SMRT.

"As we await the reply from the company on their decision, we will continue to render the necessary support and assistance to the affected employees during this difficult time," Mr Yong said in a statement.

Mr Rahmat, who was dismissed last Tuesday (Sept 13) following an internal disciplinary inquiry, was driving the train which hit and killed two men near Pasir Ris MRT station on March 22.

The deceased - Mr Nasrulhudin Najumudin, 26, and Mr Muhammad Asyraf Ahmad Buhari, 24 - were part of a 15-men team sent out to investigate a possible fault with track equipment.

The other SMRT staff who was fired is believed to be part of the work team on the tracks.

Following investigations, SMRT said in April (2016) that several safety lapses were found, including allowing the train to ply in an automatic mode. Watchmen who were supposed to keep a lookout for approaching trains were also not deployed that day.

Besides the dismissals, verbal and written warnings were issued to other staff, and individual performance grades were "recalibrated downwards across various levels of the Trains team, including senior management," the company said in an internal e-mail to staff.

Mr Patrick Nathan, SMRT's vice president of corporate information and communications, said: "SMRT has received the appeal from NTWU with regard to the dismissal of the two staff. We will be examining the appeal in accordance with established processes."