Five men aged between 21 and 40 have been arrested after a rioting incident in Clarke Quay on Saturday night that involved a deadly weapon.

The brawlers had fled the scene in Eu Tong Sen Street by the time the police arrived after being alerted at about 10.40pm, while members of the public were helping two injured people. The Straits Times understands that a flick knife was the weapon used in the fight.

A 27-year-old woman and a 36-year-old man at the scene were conscious when taken to the Singapore General Hospital (SGH). A 29-year-old man was arrested for disorderly behaviour.

A 40-year-old man suspected of being involved in the fight was found hiding in a dark corner of a back alley near Carpenter Street. He was arrested and taken to SGH to have his injuries treated.

Investigations by officers from the Central Police Division and Criminal Investigation Department, as well as closed-circuit television footage, helped identify some others involved in the brawl.

"Four men, aged between 21 and 34, were arrested within 16 hours following the incident. A manhunt is under way to arrest the other suspects involved," said the police in a statement yesterday.

Preliminary investigations found that the fight erupted after a dispute in a nearby restaurant.

The police are still investigating the case.

A video uploaded by Facebook user Navin Kumar, which has garnered more than 80,000 views, shows several people shoving each other outside The Central mall in Clarke Quay. A woman can be heard screaming as several men, including one who had taken his shirt off, fight each other on the walkway leading towards an underpass outside the mall.

The video then cuts to the point when the police have arrived. Officers can be seen using torches and breaking up another scuffle between two men on the footpath in front of the mall.

Near the end of the three-minute video, blood is seen splattered on the wall and floor of the walkway as paramedics tend to a man lying down, as well as a woman who is seated on the side of the path.

The police said they will not tolerate "such brazen acts of violence and blatant disregard of the law" and "will spare no effort to apprehend such offenders and deal with them in accordance with the law".

Offenders convicted of rioting while armed with a deadly weapon can be jailed for up to 10 years and caned.