Australian Open chiefs have been warned to urgently scale up security around the tournament amid heightened tensions in Melbourne after the Novak Djokovic furore.

Analysts have warned of “inevitably febrile” scenes at the Rod Laver Arena, whatever is decided by border authorities considering the apparently unvaccinated Serbian’s visa bid.

Opposing groups of protesters – including scores of anti-vaxxers – have been gathering outside the quarantine hotel of the world No 1 tennis player ahead of his hearing with authorities.

As some 200 demonstrators rallied outside Melbourne’s Park Hotel on Saturday, security experts said tennis organisers should be “rapidly” escalating their plans.

“You really cannot ignore the change in the risk profile now,” said Alex Bomberg, whose Intelligent Protection firm provides security for athletes and the celebrity world. “If you’ve got people that are angry, you’ve got to have additional plans for the venue, the hotels and transportation. You’ve got to give people the moment to protest, but you’ve also got to not let that get involved in troubling the tournament.”

Bomberg said a security presence akin to football policing will be needed. Trouble at tennis tournaments around the world is rare, but violence has flared before in Melbourne. In 2009, fans from the Serb and Croat communities clashed, hurling chairs and missiles at each other and injuring an innocent bystander.

Two years earlier more than 150 Serb and Croat fans also attacked each other with flagpoles, bottles and boots. In 2008, the tournament was also overshadowed when police used pepper spray to subdue rowdy Greek fans.