Police watch as a van carrying terror suspects arrives at Sydney's Central Court Tuesday, Nov. 8, 2005

Police in Australia have arrested at least 17 people including a radical Muslim cleric, in a series of counterterrorism raids in both Sydney and Melbourne. The police say stockpiles of explosives and chemicals were found and the operation prevented a large-scale attack.

In one of the largest counterterrorism operations carried out in Australia, more than 400 security agents and police officers supported by helicopters took part in raids in Melbourne and Sydney in the early hours of Tuesday morning.

Police shot and seriously wounded one suspect after coming under fire in Sydney. A bomb squad robot was deployed to search the victim's belongings.

Security forces did not go into detail but New South Wales police Commissioner Ken Moroney says the action prevented a 'catastrophic' attack.

"We believe we've been able to significantly disrupt a proposed terrorist attack here in Australia," he said. "That doesn't allow us any degree of complacency because, as we now place people before the courts… we know from overseas experience that certainly other persons are prepared to take the place of individuals."

Nine men appeared in a Melbourne court Tuesday, where they were charged with terrorism-related offences.

Prosecutors alleged the defendants were committed to carrying out violent attacks in Australia and had received military-style training.

One of the men charged is a Muslim cleric, Abu Bakr, who earlier this year praised al-Qaida terrorist chief Osama Bin Laden on Australian television.

These arrests follow changes last week to Australia's counterterrorism legislation, which give police broader powers to detain suspects without a specific threat being identified.

There has never been a major terrorist attack in Australia but its citizens have been targeted overseas. Eighty-eight Australians died in bombings on the Indonesian island of Bali in October 2002 and their embassy was attacked in the Indonesian capital Jakarta in 2004.