Australian Prime Minister John Howard is unveiling a government advertising campaign advising the public how to look out for potential terrorists. The campaign begins as the country is in a heightened state of alert, after bombings in Bali in October, in which many Australians were killed.

Prime Minister Howard says the campaign is not designed to cause alarm, but seeks to use the eyes and ears of the community to boost Australia's defenses against terrorism. People will be urged to report anything out of the ordinary to a telephone hotline.

Mr. Howard says the campaign, using newspapers, radio and television, is meant to inform and reassure the public.

The advertisements start on Sunday, and will run for three months. A booklet on terrorism prevention in 28 languages will be sent out to households in late January.

The advertisements show security forces checking for car bombs and x-raying airline baggage, as well as people playing cricket and surfing. The messages urge people to report suspicious behavior.

Critics of the unprecedented campaign warn it might whip-up public hysteria and racial stereotypes. Some Muslim groups express strong reservations about the idea. They say that, since the attack in Bali more than two months ago, which killed nearly 100 Australian tourists, attacks on Muslims in Australia have surged.

Prime Minister Howard insists the anti-terror campaign will not divide the community, and says he does not believe Australia's Muslim population will be singled out.

The government has set up a national security Web site to keep Australians informed of security-related issues, such as health preparedness in case of biological or chemical attack.

In Sydney, meanwhile, the police say they plan to ban cars from the city center ahead of New Year's Eve celebrations. A million people are expected in the downtown area for the celebrations.

Last month, the authorities warned they had received a 'credible threat' of an attack on Australian soil before the end of January.