A moving train collided with a stationary faulty train at the Joo Koon station in the far west of the city state, said the Land Transport Authority (LTA).
Twenty-three passengers and two Singapore Mass Rapid Transit train (SMRT) staff sustained "light to moderate injuries" and were taken to hospitals, the LTA said.
"At 8.19am, a second train stopped behind the first faulty train. At 8.20am, the second train moved forward unexpectedly, and came into contact with the first train," the LTA and the SMRT said in a joint statement.
The last time that an MRT train collision happened in Singapore was more than two decades ago, according to a report by the Channel News Asia today.
That incident, a front-to-back collision between two trains at Clementi station on August 5, 1993, resulted in 156 injured commuters.