He said police had been monitoring the teenagers "for some time" before the arrests. "It's a number of street gangs that are in conflict with each other," he said. Young people on the streets during the Moomba 'riots' of 2016. Credit:@russmulry, via Twitter "There's territorial disputes ... and also we're actively monitoring the interaction of these groups." The 16 teenagers were all arrested during a string of police search warrants executed across Melbourne's south-east early on Tuesday.

Police said the warrants were sparked by an affray at a home on Barkly Street in Footscray on July 31 where a group of young people allegedly entered the premises with weapons and assaulted four people who were inside. A number of the young people were arrested over their role in the Footscray incident and some were also involved in other "unrelated" affrays and violent incidents, in Hallam and Oakleigh on August 9 and Dandenong on August 14, police said. North West Metro Regional Crime Squad Detective Senior Sergeant Marnie Sheehy said police would not tolerate public violent incidents that put the safety of others at risk. Mobile phones seized during the dual raids will also now be examined. “Simply put – police will not tolerate those who break the law or engage in anti-social and violent behaviour that puts the safety of others at risk,” Detective Senior Sergeant Sheehy said.

“It’s really concerning to see so many young people facing court on serious charges including affray and violent disorder. “We can’t forget the impact violent crime has on the rest of the community, it causes an unacceptable level of harm and fear. " Huge crowds are expected for this year's White Night. Credit:Luis Enrique Ascui The 16 males, who've since been charged, include teens aged from 15 and 18 from Hallam, Clyde North, Berwick, Pakenham, Dandenong and Doveton. The others come from Cranbourne's north, east and west.

A 17-year-old from Doveton, 15-year-old from Cranbourne and 18-year-old from Pakenham have also been charged with bail related offences. The remaining 13 were bailed to appear at court at a later date. Mr Hansen said police hoped the raids had “dismantled and disrupted” those networks. The senior officer said the raids were a “first wave” of operations “related to a broader group of people that are networked and connected”. “When opportunities present to us, for us to take them out of the picture and make sure the broader community is safe, we’re actively seeking those opportunities,” Mr Hansen said.

Mr Hansen said gang members were not of any particular ethnicity and police were monitoring people of all backgrounds. "Over the course of White Night, we're being supported by community leaders from the African community, from the Maori community and from the broader community. We will have a number of community leaders out with us on patrol Thursday, Friday and Saturday night," he said. The riot at Moomba in 2016 involved scores of youths believed to be members of gangs then known as Apex and Islander 23. It is not known if members of the same gangs are involved in the current escalating tension. "These gangs have been with us for some time," Mr Hansen said.

"They are fluid in size - they change - people come in and out of those gangs, so they morph quite a bit. They change names from time to time. There is a level of connection that occurs across social media predominantly. "Some of these relationships are born out of when kids are in custody." Mr Hansen said there would be "north of" 500 officers on the ground in Melbourne's CBD from Thursday night, in what he described as one of Victoria Police's most "resource heavy" events. He warned people planning on causing trouble police would be waiting. "We aren't scared of them, we aren't afraid of them and if those people want to come into the city on the weekend and cause problems then ... we'll be here waiting for you," he said.

"We're hopeful that the main players who we believe are going to cause a risk to community safety won't be in a position to do that, through White Night," he said. Police and event organisers have been developing a plan to thwart a potential riot or hostile vehicle attack since the beginning of the year, according to White Night director David Atkins. Mr Atkins – who commended police for the arrests – said a “massive” number of police officers and more than 200 event security staff will be watching for any disruptive behaviour. Victoria Police will also launch Operation Omni on Friday and Saturday nights, giving police increased search powers in the CBD and festival area. The powers will include increased powers to stop, search and ask for names and addresses, Mr Hansen said.