A man who allegedly pointed a gun at guests and staff in the lobby of a city hotel has been arrested by heavily armed officers after a wild police chase.

Tactical officers swarmed Melbourne's city centre on Tuesday morning with unmarked police cars blocking Spring Street near Victoria's parliament.

Witnesses watched as heavily armed police raced through the streets in search of the man, believed to be carrying a gun, before surrounding him at a nearby hotel.

A staff member at the Hotel Lancemore in Crossley St, who didn't want to be named, said the man walked into the hotel and pointed a gun at him, sending him running.

"It was such a fright," he told AAP.

Hotel guest Humberto Aguilar said he was downstairs in the lobby waiting outside the toilet when he saw armed police.

"I hear a guy scream out ... he put the gun in front of me," he said.

"I put my back to the wall and ran outside."

Port Melbourne resident Xavier was on his way to community school in Richmond when he saw a silver four-door Hyundai "flying" through the streets.

The 14-year-old said the driver was trying to hit people and wouldn't stop.

"I was near Flinders St, I almost got hit by the guy who was driving," he said.

"I had to run outside of his way.

"He was going about 100km/h on the tram tracks ... and then he jumped off the gutter."

A police helicopter was seen hovering over the area for more than half an hour.

Police later confirmed they arrested a man wanted over two carjackings in Tarneit and North Melbourne earlier in the day.

They said he had a firearm and was taken into custody to be interviewed.

During his arrest the man was heard crying out in pain before he was stretchered out of the hotel and into an ambulance.

The show of force comes just a day after Victorian police chief Mike Bush announced sweeping changes to the organisation that would see more police ditch the desk and get back on the beat.

Mr Bush, who served as New Zealand police commissioner from 2014 to 2020, took over the role in June after a period of leadership turmoil and unrest within Victoria Police.

He spent most of Tuesday morning spruiking his plans to Victorians in interviews on both TV and radio.

"We are extremely concerned about the level of crime that occurs on our streets," the chief commissioner told Nine's today program just after 8am as he outlined plans to reorganise the police force to enhance visibility and prevent crime.

Fresh data from Victoria revealed the state is enduring the worst crime surge in its history, including 5400 individuals arrested 10 times or more in the year to June.

Accused carjacker 'pointed gun in hotel' during chase