SINGAPORE - A 22-year-old man who repeatedly punched a 68-year-old man in the face for allegedly molesting his girlfriend was on Monday (March 28) jailed for six weeks.

Shawn Ho Wee Kiat pleaded guilty to causing hurt.

A district court heard that at about 1.30pm on Aug 2 last year, Ho's girlfriend Ms Choo Wan Sheng, also 22, was queuing to buy food at the coffee shop at Block 59 Marine Terrace when she twice felt the elderly man behind her bump into her.

An argument broke out, with Ms Choo threatening to report Mr Tham Wye Mun, 68, to the police for molest, and Mr Tham challenging her to do so.

Ms Choo then returned to Ho's home, where she was staying over, and told Ho and his mother, Madam Chua Bee Gek, 42, about the incident.

At about 1.45pm, all three went to the coffee shop to look for Mr Tham, who was still there.

Madam Chua accused Mr Tham of molesting Ms Choo and flung a cup of tea at him. Mr Tham retaliated by throwing his plate of half-eaten noodles at Madam Chua.

Ho then punched Mr Tham in the face with both his fists several times, and the latter fell to the floor.

When he got up, Ho continued to punch him, and the man fell to the ground again.

Ho also shouted profanities at Mr Tham.

When Mr Tham tried to walk away, Ho tore off the older man's T-shirt and insisted that he apologise to Ms Choo.

But Mr Tham maintained he was innocent.

Two members of the public separated the two men.

Mr Tham suffered a nose fracture, and swelling and abrasions on his face. He was given three days of medical leave and referred to an ear, nose and throat specialist.

The prosecution asked for six to eight weeks' jail, noting that Mr Tham was an elderly and vulnerable victim.

"The attack was a persistent one and disproportionate to whatever 'offence' that the accused might have perceived," said Deputy Public Prosecutor Jason Nim.

For causing hurt, Ho could have been jailed for up to two years and fined $5,000.