Top cop talks tough

Organisers of the Sydney Olympics will not tolerate violent protests from anti-corporate demonstrators who disrupted a World Economic Forum meeting this week, Sydney's top policeman said on Wednesday.

Anti-globalisation protesters have caused havoc at the WEF meeting in Melbourne over the past three days, where they have clashed with police in a series of often violent protests.

Mounted police were called in to protect delegates, many of whom were unable to enter the forum venue for an event dubbed the "Business Olympics".

New South Wales state police chief Peter Ryan said he believed some of the loose alliance of protesters might come to Sydney for the Olympics, which feature many leading corporate heavyweights as sponsors.

"We will not tolerate this city being closed down. We will not tolerate any disruption to the Olympic Games," Ryan told Channel Nine television.

"I think it's likely that some of them will come up to Sydney and join in with other protesters against various things that they want to demonstrate about," he said.

Teams of police charged about 500 protesters outside Meblourne's Crown Casino on Tuesday as delegates attempted to leave for a dinner with Australian Prime Minister John Howard.

Helicopters buzzed overhead and at least three protesters were arrested on Tuesday in some of the worst protests ever seen in Melbourne. Nine people, including a handful of police, were hurt during clashes.

Many of the business leaders who attended the WEF Asia-Pacific forum, including Microsoft Corp chairman Bill Gates, intend to travel on to Sydney after the WEF meeting ends in Melbourne later on Wednesday.

Security was tight from the outset in Melbourne with protests expected from the umbrella alliance S11, named after the September 11 start date, and officials fearing a re-run of the chaos at last year's World Trade Organisation meeting in Seattle.

Olympic security chiefs have identified up to 100 potential sites for disruption at the Games, although security sources have said not one single credible threat to the Sydney Games has yet been received.

Australia's Aborigines, the country's most disadvantaged group which make up about 2.1 percent of the 19 million population, have vowed to stage peaceful protests throughout the Games in an attempt to draw international attention to their plight.

Ryan said police and organisers would allow peaceful demonstrations to go ahead during the Games, which are officially opened on Friday.

"But if they insist in this violent confrontation which we've seen in Melbourne over these last three days, we will act very, very firmly against them," he said.