SINGAPORE - A man who slapped a six-year-old boy in the face because he believed his mother had not disciplined him firmly enough was fined $5,000 on Wednesday (Jan 10).

Liow Chuan Tiong, 52, was chatting with friends at a playground when he saw a woman reprimand her son after he spit in a girl's face, a court heard.

The mother asked the boy to apologise, which he did in front of the girl's mother.

But Liow felt that the child had not been disciplined enough.

He walked up to the boy and slapped him once on the right cheek, causing mild swelling and redness.

The victim's mother shielded her son and led him away before calling the police.

Liow was fined after he admitted slapping the victim at the playground in Boon Lay Avenue at about 7.30pm on Oct 8, 2016.

Deputy Public Prosecutor Grace Chua asked that Liow be given the high fine of $5,000, citing the age and vulnerability of the victim.

She said he had no business to assault the victim, who cannot be named due to a gag order.

Pleading for a light sentence, Liow, who was unrepresented, said his own child was still studying at the Institute of Technical Education.

Liow said he himself had started working four months ago but did not reveal his job.

"I have learnt (from) my mistake," he added.

District Judge Kessler Soh said he did not understand why Liow took it upon himself to hit a child.

"Learn from this lesson, and do not allow yourself to lose your cool at all times," he told Liow.

Liow paid $1,000 on Wednesday and will pay the balance through eight monthly instalments of $500 each.

He could have been jailed for up to two years and/or fined up to $5,000 for voluntarily causing hurt.