Extra police powers and resources could be created in the fight against gang crime after young men stormed the Melbourne CBD during Moomba festivities, attacking and robbing people.

With members as young as 12, the Apex gang – a loose affiliation from a range of cultural backgrounds – stole phones, taunted police and terrorised people on Saturday night in full view of CCTV cameras in the city.

Police were warned there was talk on social media of such violence, but Deputy Police Commissioner Andrew Crisp said on Monday they were surprised by the number of gang members involved.

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Premier Daniel Andrews slammed the youths for threatening public safety.

“Regardless of your background, most of us know right from wrong and the behaviour on Saturday night was wrong,” Mr Andrews said.

“It was an evil choice and one that those involved will deeply regret.”

He did not rule out introducing legislation to tackle the gang violence, saying they would provide police with the powers and resources they need.

“We will not hesitate in making sure Victoria Police have got what they need to smash these gangs and keep Victoria safe.”

There was a heavy police presence in the city on Sunday night after the gang threatened on social media to return to run amok again. They did not turn up.

A new task force has been created to examine hours of CCTV footage that captured the violence and thefts on Saturday.

Another operation, Taskforce Tense, was set up in November last year to deal with the gang and a spate of home invasions across the suburbs.

Opposition police spokesman Edward O’Donohue said if two task forces were being dedicated to dealing with gang crime, more police were needed.

“All these challenges to community safety requires a strong response and police need the resources,” he said.

Despite the riot at Federation Square on Saturday, many families spent Labour Day in the CBD for the Moomba Parade, in which the Moomba Queen and King were Melbourne Cup-winning jockey Michelle Payne and her strapper brother Stevie.

-AAP