Phil, a witness who was riding his bike around 6am on Sunday in Collins Street said he saw about five men fighting, near the corner of King Street.

When police arrived, four of the men left but one man, 29, of Keilor, remained, allegedly charging at police.

"This dude he was too much for them he was running through them and they ended up having to Taser him and pepper spraying him," Phil said.

"He was just covered in it.

"He was swearing, calling them filth and dogs," Phil said.

"When they had him down on the ground they were pushing down on him and he was struggling to breathe," he said.

Ten police cars were called to the scene.

Assistant Commissioner Andrew Crisp said police had responded to a "drug affected" male "carrying on in the street" when police approached the Keilor man.

"I have been briefed that he ran or moved towards them to take them on," Mr Crisp said.

"They deployed OC spray and that's not had a total effect on that individual," he said.

He confirmed police then used a Taser to control the man. He was taken to St Vincent's Hospital suffering the effects of capsicum spray.

Senior Sergeant Ciaran Boyle said police were injured in the arrest.

Ambulance Victoria confirmed three police officers were taken to the Epworth Hospital with minor injuries, including a hand and an arm injury and suffering the effects of capsicum spray.

Yusef, of Roxburgh Park, was caught in the capsicum spray crossfire as he drove home from a night out with friends.

Yusef said a malfunction with his navigation system put his car in the line of fire.

He was on his way home from Crown Entertainment Complex when his navigation system sent him down King Street. Realising his mistake he made a U-turn only to find police attempting to arrest the man in Collins Street.

"He was running and I was turning left (into Collins Street). I saw police officers trying to catch that man and they were using capsicum spray on him. It got on my bonnet and then the spray got on me through the (passenger) window," Yusef said.

He said he could see police getting the man to the ground through his squinting eyes.

"He was on the ground and covered in capsicum spray, just covered, he was bleeding," Yusef said.

He said he was given water to flush out his eyes.

"It's OK I can drive with one eye shut," he said.