Carl Scully, the police minister for New South Wales, confirmed on Wednesday that officers would continue to be on high alert after more than 400 police officers maintained calm overnight in the affected suburbs, including Cronulla.
Hundreds of cars were subjected to police checks, and five men arrested for carrying weapons. A similar operation began on Wednesday night.
Authorities were investigating whether a fire in the early hours of Wednesday at a Protestant church hall in a Sydney neighbourhood with a large Middle Eastern population was linked to the unrest.
Vandals smashed several windows of another church nearby.
The chief executive of the Australian Federation of Islamic Councils, Amjad Ali Mehboob, said worshippers at the local Omar Mosque would, in a show of solidarity, hold a meeting with members of the Christian congregations on Friday.
State political leader Morris Iemma said police would keep a close watch on places of worship in the days to come.
"Special attention will be paid to places of worship, our churches and our schools," he said. "These hooligans and criminals will not destroy the fabric of our society."
Alcohol-fuelled violence erupted
in Cronulla on Sunday
Scully said telephone text messages inciting violence were continuing to circulate in Sydney and other Australian cities.
The new text messages are apparently similar to ones last week that encouraged a mob of 5000 white Australians, including some neo-Nazis, to gather at Cronulla beach in southern Sydney and attack police, paramedics and people of Middle Eastern appearance.
"We need to be aware that there is a risk of incidents continuing," Scully said. "On the weekend, there will be a huge police presence across Sydney on Saturday and Sunday."
Youths of Middle Eastern appearance retaliated with a rash of attacks on people and property on Sunday and Monday nights.
Nearly 40 people have been injured and 27 arrested since the disturbances began.
Iemma said on Wednesday that one man has been jailed for four months for carrying an offensive weapon - a tree branch - in public.
At the same time Muslim community leaders and representatives of Sydney's "surf movement" met for what they billed as a "mission of peace".
Brad Whittaker, who described himself as a representative of the beach culture community in Cronulla, said the violence must end and apologised for some of his members.
Police will get tough new powers
to handle the situation
He was reported on local radio as saying: "The day began as a show of solidarity against behaviour of ethnic gangs that have been harassing the public on our beaches over a period of seven years. It escalated out of control under the influence of right-wing racists from outside this community, and (the influence of) alcohol."
Anger towards groups of young Lebanese men in Sydney has been simmering for years.
A gang rape case in 2002 exacerbated tensions. Members of a Lebanese gang hurled racial abuse at their rape victims, all of whom were white.
Tensions have also been fuelled by anti-Muslim sentiment stemming from the 9/11 terror attacks in the US and deadly bombings on the Indonesian island of Bali that killed 202 people, including 88 Australians, in October 2002.
Six of the Bali victims were from Cronulla.
Iema announced that lawmakers planned to give police tough new powers, including shutting bars and erecting roadblocks, to crack down on rioters and keep the peace.