As of 10am, about 150 protesters had gathered at the corner of Elizabeth Street and Victoria Parade, some chanting "f--- the jab".Speaking to Today, the CFMEU leader said he attempted to calm the riled-up mob but the environment turned hostile.
"You couldn't even talk - we tried to keep it all calm, and it just got out of control," Mr Setka said.
"People started throwing bottles. Some of them were fighting amongst themselves.
"You know, once they started throwing the bottles, that was it - we just said this is too dangerous, let's move back in.
"It just got out of control from there."
© Nine CFMEU union boss John Setka has slammed the mob of protesters for violently protesting outside his office.
A number of protesters were arrested.
Mr Setka has claimed the majority of the protesters were not construction workers.
"There was a sprinkling of construction workers there, of our members, and the rest were just people, I wouldn't even know who they are," he said.
"All the rent-a-crowds were there, professional protesters.
"A few of them anti-vaxxer activists were there - who are not union members, they're not from our industry - and they're the ones you see at all the protests.
"Thanks to these morons, 300,000 Victorians are sitting at home for at least the next couple of weeks, it could drag out even longer."
The $22 billion Victorian construction industry has been shut down for at least two weeks in response to the violent protest and "widespread non-compliance" with COVID-19 restrictions, as transmission continues to rip through the sector.
Treasurer Tim Pallas confirmed the shutdown last night, about two hours before it came into force at 11.59pm.
