THREE men were "monstered" by a group of at least six in a serious street attack in central Invercargill in the early hours of Saturday morning, police said.

The men were attacked moments after the vehicle they were travelling in crashed in Gala St.

Sergeant Wing Ng said police were called to the scene just outside Rices Powerstore.

A group of Murihiku Maori Wardens reported three men, aged in their mid-20s, had been attacked.

Police were investigating the circumstances leading up to the attack, but believed an altercation between the men who were attacked and the group that attacked them had taken place only moments earlier as both groups drove around the inner city, Mr Ng said.

"The victims were in a silver Ford Replica Pulsar Watches Falcon and the offenders in a red van when there was an altercation at the Trooper's Memorial (the roundabout at the intersection of Tay and Dee streets)," he said. "I don't know if words were exchanged or bottles were thrown."

Both vehicles travelled north in Dee St, before turning into Gala St, where the driver of the Falcon lost control of the vehicle, Mr Ng said.

"The Falcon crashed and the van pulled up and the occupants leapt out and monstered the other men."

The first officer on the scene, Mr Ng said the van carrying the offenders had left before he arrived but witnesses said it had driven off south in Leven St.

After he radioed another police unit, the van was pulled over several blocks away, he said.

Police arrested the occupants of the van, five men and one woman, aged between 19 and 39, he said.

The six made a brief appearance in the Invercargill District Court charged with injuring with intent to cause grievous bodily harm later that day.

They were remanded in custody to appear in the Invercargill District Court tomorrow. He could not discount the possibility of additional charges.

Two of the three men attacked were taken to Southland Hospital with facial injuries and later discharged, Mr Ng said.

Inquiries were continuing.

Police were asking anyone who witnessed an incident between the occupants of the red Ford Econovan and the silver Ford Falcon in Dee St, or the subsequent assault, to contact Invercargill police.