SINGAPORE - It started with a chance meeting between two female students romantically linked with the same man and ended in a six-on-one assault in a karaoke lounge.

Ms Zheng Lu was left with many scratches on her body after being set upon by Wang Xi, 24, and five others on May 3 last year.

Wang had suspected Ms Zheng, 19, of having an affair with her boyfriend. She grabbed Ms Zheng by the hair as the victim was walking around the outlet, pulled her top and pushed her to the ground.

The six attackers then used their hands to strike the victim. Two others had to intervene to break up the scuffle.

The six are: Wang; sisters Wu Huachun, 20 and Wu Huamin 19; homemaker Liu Jiabao, 31; and working professionals Ding Jiao, 29, and Qiu Zhulin, 28.

All are Chinese nationals except Ding, who is Singaporean. Two of them are permanent residents here.

On Wednesday, the six were fined between $1,000 and $2,000 for hurting Ms Zhang at K-Box in Cineleisure Orchard at 2.15am.

Wang and Wu Huachun, who had both also kicked and punched the victim three hours earlier, received the stiffest fines of $2,000 each.

The lightest fine of $1,000 went to Wu Huamin, who had come later to accompany her older sister home. The others were at the outlet all along to celebrate the first month of a friend's baby.

Meanwhile, Ms Zheng had also come for a karaoke session but was moving to a VIP area to join a friend's birthday celebration.

Defence counsel Surian Sidambaram said Wang had earlier tried to confront Ms Zheng on the phone over the matter but was rebuffed in her attempts to set up a meeting.

She saw Ms Zheng and her emotions got the better of her, the lawyer said. He added that Wang and her boyfriend are no longer together.

District Judge Victor Yeo said it was "fortuitous" the victim had not suffered serious injuries, considering she had clearly been outnumbered.

He agreed that the attack had not been planned, noting also that Ms Zheng had forgiven her attackers and was not seeking any compensation.

Each of the six attackers could have been jailed for two years and fined up to $5,000 for voluntarily causing hurt.