A group of fans was barred from the Australian Open on Monday after letting off flares nearby, recalling violent disturbances that have previously marred the Grand Slam tennis tournament.
Police said they will study CCTV footage and hope to bring charges after the group of 15-20 men let off a series of flares just metres (yards) from the venue in central Melbourne.
"A group of about 15 to 20 males were walking along the side of the Yarra (river) … and a couple of people in that group have let off some flares which is very dangerous behaviour," Inspector Trevor Cornwell said, according to the Herald Sun.
"We're still ongoing with our investigations in regard to the males, we're reviewing some footage that we have," he added.
Footage online showed several flares burning in a riverside park near the Australian Open venue, which was packed with thousands of fans on day one.
Cornwell said some of the group were wearing "national flags of a European country" but that the incident was not "race-related".
In extraordinary scenes for a tennis tournament, the Australian Open was marred by fighting involving ethnic Serbian, Croatian and Bosnian fans in 2007 and 2009.
Ahead of this year's event, police warned troublemakers would not be tolerated.
"Anyone caught causing trouble at the event can expect to be evicted or even face charges under the Major Sporting Events Act," said Superintendent Peter O'Neil.