LAUGHING and jeering, two women egg on brawlers as they throw punches and kicks when a group of Australian Defence Force personnel were allegedly set upon in an early morning clash.

Running along behind as the fight spills along the Kings Cross red light strip, the women giggle with glee as the violence escalates.

Police have branded the conduct of the two beanie-wearing women as "concerning and deplorable".

The off-duty soldiers were allegedly attacked as they finished a night out in the Cross, just after 3.30am.

Up to six men picked a fight with the soldiers, which police said started as a verbal altercation and escalated into violence.

At the height of the fight, one of the alleged attackers was seen to remove the belt from his trousers to use as a weapon.

Police said the fight began near the Crest Hotel in Darlinghurst Rd and moved to the nearby Goldfish bar.

"It went from corner to corner, from footpath to footpath and roadway to roadway," Detective Inspector Paul McDonald said.

Two men, not ADF personnel, were arrested and charged with affray and offensive behaviour.

Central Local Court heard one of the men charged, 20-year-old Agok Machol, had a history of violence and had breached good-behaviour bonds for intimidating police and assault. Police prosecutor Sergeant Michael Morris said Machol was the aggressor in an "unprovoked" attack on the victims, which had been captured on video.

But the 20-year-old, who pleaded not guilty to the charges, claimed he only got caught up in the melee after rushing to the defence of friends.

His lawyer Anne Roy said Machol had been waiting to get into a nightclub when the brawl broke out.

"He saw his two friends in the distance being attacked by approximately six males and he went over to stop them," she said.

Ms Roy said the video footage only showed the end of the brawl.

Magistrate John Favretto said Machol's actions were "a matter of serious violence" that involved kicking a man to the ground.

"He was also seen to change clothes, no doubt to escape detection," he said.

Machol was refused bail to reappear in court in July.

Another man, an un-named 21-year-old, was granted bail and will face court next month.

Chief of Defence General David Hurley and Defence Minister Stephen Smith said an internal investigation would be conducted to try to discover exactly what happened.

"I'm disappointed that ADF personnel have been involved in this," Mr Smith said.

"But it's too early to make any calls or draw any conclusions about what's happened here."

Originally published as Girls jeer as Diggers bashed by mob