SYDNEY (Reuters) - Australians were warned on Friday to stay away from beaches in three cities this weekend with police saying they have credible evidence that racial violence was being planned. Police urged people to avoid Cronulla Beach in Sydney's south, where racial violence first flared last Sunday, as well as eastern suburbs beaches which include Maroubra and Bondi, and beaches in regional coastal cities Wollongong and Newcastle. "Our latest intelligence tells us that large numbers of people are planning to go to these areas on Sunday to cause riotous behavior," New South Wales state Police Commissioner Ken Moroney said in a statement on Friday. "I would urge people who do not live in these areas to stay away unless they have a good reason to be there," Moroney said. "It is my duty to warn the public that these areas have been identified as targets." Racist text messages and emails have been circulating calling for violence this Sunday -- the one week anniversary of the unrest -- and media reported talk of Lebanese youths calling themselves the "lions of Lebanon" coming from across the country to fight this weekend. Sydney's racial violence erupted at Cronulla when thousands of people, some yelling racist chants, attacked people of Middle East appearance, saying they were defending their beach from Lebanese youth gangs. Police said white supremacists incited violence at Cronulla. Lebanese and Muslim youths retaliated with two nights of violence in several different beachside suburbs. A major police crackdown restored calm, but a Molotov cocktail was thrown at police, a stockpile of incendiary devices uncovered, and 19 people arrested in Sydney on Thursday night. Police will launch the biggest security operation since the 2000 Olympics in a bid to halt further racial unrest. Up to 1,500 police, triple the current number on the beat, will be on the streets on Saturday and 2,000 on Sunday. "There will be lockdown areas. There will be areas where alcohol can not be consumed or purchased," said NSW Police Minister Carl Scully. "There will be roadblocks and cars confiscated and people arrested. It will be zero tolerance. We will not put up with any nonsense," Scully told local radio. A police command center has been established on the same lines as if Sydney faced a "terrorist threat," said Assistant Police Commissioner Andrew Scipione. "This is a long-term fight to ensure the hooligans, thugs and criminals who want to create trouble and disorder will not win," Morris Iemma, NSW state premier, told reporters. Arab-Muslim leaders and beachside communities have held "peace talks" and called for an end to the violence. Invitations have been sent to 28 Lebanese leaders to attend the launch of a surfboat at Cronulla Beach on Sunday, while the Cronulla surf lifesavers club has launched a drive for Lebanese membership. The Australian newspaper reported on Friday that Lebanese youths, calling themselves "the Lions of Lebanon," were talking about heading into Sydney, intent on violence. "We're expecting about 30 cars and a couple of busloads of Leb, Serb, Italian and Greek lions to punch on with us," said a young Lebanese man in the southern city of Melbourne.