Police arrested four people over a fight in a Mong Kok restaurant early on Sunday morning that allegedly began when a group of men confronted a woman over money that they claimed to be owed.

The 41-year-old Vietnamese woman, who holds a Hong Kong identity card, told police she was eating at the restaurant in Shanghai Street with her boyfriend at 1:20am when 10 men arrived. A man called Kot demanded payment of a debt, but the woman said it had been settled.

She was then attacked by the group of men, with the boyfriend, a 31-year-old Pakistani, coming to her aid, Sing Tao Daily reported. Kot is alleged to have then threatened them with a knife from the kitchen.

The couple were arrested, along with Kot, 39, and a 51-year-old man with the surname Yip. They were charged with fighting in a public area, while Kot faces an additional charge of possession of weapons.

All four were injured in the incident, but declined hospital treatment.  Police are still looking for the other eight men.