They are believed to have been hit by on oncoming train.
The incident happened at around 11.10am.
The two Singaporean workers are 26-year-old Nasrulhudin Najumudin and 24-year-old Muhammad Asyraf Ahmad Buhari.
SMRT says they were undergoing on-the-job training when they were killed.
The two men joined SMRT in January this year.
They were responding to a reported alarm from a device linked to signalling equipment.
Nasrulhudin and Asyraf along were walking along the left track when they tried crossing over to the right track.
That’s when the train crashed into them and killed them.
A third technician managed to escape.
The incident caused a 2-hour suspension of train services between Tanah Merah station and Pasir Ris station.
SCDF officers subsequently removed the bodies of the two men.
In a similar turn of events, a 48-year-old technician was hit and killed by an LRT train while investigating a track fault.