Police outnumbered bathers on many Sydney beaches Sunday in an unprecedented effort to prevent more of the racial rioting that hit Australia's largest city last weekend. More than 2,000 police in patrol cars, inflatable dinghies, planes and helicopters and on bicycles and horseback kept a close eye on potential trouble spots a week after more than 5,000 mainly white youths, many of them drunk, fought a series of skirmishes with police and attacked people of Arab appearance. On Sunday at Bondi beach, normally busy restaurants and bars - and the sand - were nearly empty. At daybreak Sunday, about 40 Christian pastors and ministers, many from Sydney's eastern suburbs and the most affected beaches, issued a call for calm in the leadup to Christmas. At Cronulla, scene of the original rioting, the pastors left behind a sign spelling out "Peace" using a combination of black plastic bags and seaweed. "As leaders in a number of religious communities within the city, some have looked to us for spiritual guidance in the wake of the racial and cultural tensions that have erupted on our beaches," the pastors wrote in a statement. Several peace rallies were scheduled in Sydney on Sunday, while at Cronulla, one enterprising person sold "Stop the Violence" badges for 4 Australian dollars. A Christmas concert planned Sunday for another beach affected by the rioting was canceled due to potential trouble. Police seized four cars Saturday night under new powers given to police this week by the New South Wales state parliament. Several arrests were made and weapons including swords and iron bars were seized, police said. Police were checking every vehicle traveling toward Cronulla beach in Sydney's south. Government officials, fearing retribution from Middle Eastern gangs from last week's rioting, called in thousands of extra police and "locked down" a number of beaches, allowing only local residents in. The police checks created massive traffic backups. But Deputy Police Commissioner Andrew Scipione said the closure of 31 roads leading to area beaches was necessary. "We apologize for the delays, and for the inconvenience, but this is not a normal weekend," he said Saturday.