There have been multiple arrests in Melbourne as police and protesters clash ahead of an expected third day of protests in the city.

The hardline approach came after the hundreds of “violent thugs” who caused havoc and shut down the West Gate Bridge on Tuesday were given a final warning to stay out of the city.

Victoria Police were given permission to use crowd control force against anyone trying to mimic the seven-hour cat and mouse game seen in Melbourne, when protesters led police across the city.

Up to 500 heavily armed officers assembled outside the CFMEU headquarters in Elizabeth Street, ahead of an expert third day of protest action on Wednesday. They were reportedly armed with smoke and stinger grenades, rubber bullets and pepper spray.

The riot squad arrived at the confrontation outside the boarded-up union building shortly before 11am. Minutes later, hundreds of fluoro and black-clad protesters began moving through the CBD to Elizabeth Street.

Earlier, Premier Daniel Andrews, flanked by state Police Minister Lisa Neville and Chief Commissioner Shane Patton, issued the warning on Wednesday morning.

“The ugly scenes that we saw yesterday are not only appalling, they’re unlawful,” Mr Andrews said.

“Victoria Police will take action against those who did the wrong thing yesterday.”

• Five more deaths, 1035 infections in NSW

The warning came as Victoria’s COVID case numbers leapt again on Wednesday, to 628.

There were also three more deaths. Mr Andrews said more details would come in a public health briefing later in the day.

Protests against virus measures began in Melbourne last week, after construction workers were told they could not have breaks in tea rooms because of the risk of spreading coronavirus.

Getting a COVID-19 vaccine was made mandatory for the industry, prompting another protest in front of the CFMEU office on Monday, which turned violent.

By Tuesday, a crowd of mostly men, clad in high-visibility clothing, took to Melbourne’s street against the state government, CFMEU and police.

Ms Neville called them “thugs”.

“If you’re thinking about coming into the city today to cause violence and harm, just know that Victoria Police will deploy whatever tactics they need to in order to ensure that you are held accountable,” she said.

“They have my full support in deploying whatever tactics they need to ensure that these thugs, these violent thugs, are unable to cause further harm to our city and to our community.”

Mr Patton has given permission to his officers to use the force to keep rioters from creating unrest again.

“You’re not going to be welcomed with open arms, I can assure you of that,” he said.

“We have significant tactics in place, we will be agile in our response, we will be very swift in our response and conduct as we have seen yesterday and the previous day will not be tolerated.”

Victoria Police have arrested 62 protesters, some for assaulting police, but most for breaching public health orders.

The mob has been described as a broad mix of people.

CFMEU Victorian construction secretary John Setka is blaming “neo-Nazis and right-wing extremists” for hijacking the event.

He urged construction workers to stay at home.

“My advice to them would be to not take part in the protest today. It’s been hijacked by extremist groups and it’s not our values,” he told the ABC on Wednesday.

The state government has shut down the construction industry for two weeks in metropolitan Melbourne, City of Ballarat, City of Greater Geelong, Surf Coast Shire and Mitchell Shire.

State health officials said on Tuesday there were 337 cases directly linked to 154 construction sites.

Of that number, 239 cases were linked to sites in metropolitan Melbourne, including nine people who lived in regional Victoria.

It is not yet known how many of Wednesday’s cases are linked to the industry.

-with AAP