Police have arrested a 52-year-old man in connection with an incident on May 2 when a nurse was hospitalised with a burn injury after sitting on what is believed to be acid on an SMRT train.
The man is believed to be responsible for a case of what police said was a "negligent act causing hurt involving unknown substances" on the seats of public transport.
A police statement released on Monday said officers from Jurong Police Division conducted extensive investigations in an effort to determine who was responsible for the incident.
They recovered key images of the man from the CCTV system.
The suspect was arrested on Sunday.
Investigations are ongoing.
When contacted, relatives of the 24-year-old victim Wan Zahfirah Arshad, who is warded at the Singapore General Hospital, said her condition is stable.
But she will need to undergo a skin graft for burns on her left buttock.
Meanwhile some commuters said they would like train operators and the authorities to step up checks while others said they would be careful before sitting down on seats in trains and at bus stops.
Separately, SMRT said it is in contact with Wan Zahfirah Arshad to ensure that she is recovering well.
It told Channel NewsAsia that passenger safety is its top priority and that it has stepped up security checks on trains and buses.
The checks include a security sweep at the start of every trip at the depots or interchanges.
SMRT said it will work with the police to do the necessary steps to ensure passenger security is not compromised.
It urged passengers to immediately alert staff to any suspicious substance or object spotted on trains and to stay away from it until help arrives.
Source: Channel News Asia