Melbourne, Jan 15 (DPA) Balkan battles flared on opening day at the Australian Open Monday with 150 troublemakers evicted from the grounds after fighting broke out between Serbian and Croatian fans.

The row broke out an hour after the start of the season's first Grand Slam and witnesses say trouble began after Serbs shouted abuses at Croatians watching their player Mario Ancic's match on a nearby court.

The incident escalated, with 40 police and security staff rushing to separate the stick brandishing, flag-waving groups, who were hurling bottles and cups of beer at each other in the Garden Square precinct at Melbourne Park.

A crowd of shocked ticket holders looked on, media reports said.

Police sought to play down the incident, saying they moved quickly to isolate the ringleaders.

The countries, both once part of the Serbia-dominated former Yugoslavia, fought a war in the early 1990s with Croatia earning independence.

Since then, the new European nation has gone on to consistent sporting glory, including winning the 2005 Davis Cup.

Serbia - with top 20 players Novak Djokovic, Jelena Jankovic and Ana Ivanovic - has begun crashing the tennis party.