Transit operator SMRT said 23 passengers and two staff suffered light to moderate injuries and have been taken to a hospital.
The incident took place at 0820 AM (0020 GMT), SMRT said in a statement.
It said a faulty west-bound train had stalled at Joo Koon station on the system’s East-West line at 8:18am.
A second train stopped behind the faulty train at the station at 0819 AM but moved forward unexpectedly a minute later, coming into contact with the stationary train.
A photograph posted on the Straits Times website showed two trains stopped and in contact but with no major damage apparent.
Earlier, the Singapore Civil Defence Force said in a Twitter post that it had been alerted to an incident at the station at 8:33am.
The collision comes as the country grapples with recent service disruptions on its mass rapid transit system, including a partial suspension of services during an October weekend due to flooding in a tunnel following heavy rains.
The mishaps led to a rare public apology by top transit executives in a country that prides itself on an efficient public service and an assurance from the government to address the causes of the various glitches.
The densely-populated city-state is highly dependent on public transport.
It is one of the world’s most expensive places to own a vehicle and recently announced that it will not allow any net growth in its car population from February next year.
More to follow…