A 12-year-old boy, who rushed to the aid of the victims of a car accident in Yishun on Tuesday, said he did so as other passers-by were "too busy taking pictures with their phones instead of helping".

Yishun Primary School pupil Ashvin Gunasegaran was walking home from school with several classmates when they heard a "loud boom" behind them as they crossed the road.

Turning around, they saw two cars had collided just metres away at the junction of Yishun Ring Road and Yishun Avenue 2.

While his friends told him to stay away as it was "too dangerous", Ashvin said he ran over to the drivers of each car after seeing that no adults were coming forward to offer assistance.

"It was my first instinct - I felt I had to check if they were okay and if they needed an ambulance," he told The Straits Times yesterday.

"One of the drivers was pregnant, she said she was not injured but asked for my help in finding her glasses. I tried to open her door but it was jammed."

Ashvin said he also checked if the other driver was fine and waited for an ambulance - called by another member of the public - to arrive before leaving the scene.

The Singapore Civil Defence Force (SCDF) said it was alerted to the accident at about 1.10pm on Tuesday and dispatched one ambulance. A pregnant woman was conveyed to KK Women's and Children's Hospital, an SCDF spokesman said. Her condition is believed to be stable.

A Facebook post by Ashvin's sister Laava, featuring a photo taken by Ashvin's schoolmate as he spoke to one of the victims in the damaged car, has been shared more than 1,700 times since Tuesday evening.

Ashvin said his classmates were cheering his name at school yesterday as the picture was shared among his peers.

"What I did wasn't special - it was just the right thing to do."