MELBOURNE, Australia — Police in Australia foiled a plot for commando-style suicide attacks on at least one army base, arresting four men Tuesday with suspected links to a Somali Islamist group, senior officers said.
Prime Minister Kevin Rudd said the plot was a "sober reminder" that Australia is still under threat from extremist groups enraged that the country sent troops to join the U.S.-led military campaigns in Afghanistan and Iraq.
Some 400 officers from state and national security services took part in 19 pre-dawn raids on properties in Melbourne, Australia's second largest city, police said. Four men, all Australian citizens of Somali or Lebanese descent and aged between 22 and 26, were arrested, and several others were being questioned Tuesday, police said.
Australian Federal Police Acting Commissioner Tony Negus said the raids followed a seven-month surveillance operation of a group of people with alleged ties to al-Shabaab, an al-Qaida-linked Somali extremist organization that has been fighting to overthrow Somalia's transitional government.
"Police will allege that the men were planning to carry out a suicide terrorist attack on a defense establishment within Australia involving an armed assault with automatic weapons," Negus told reporters. "Details of the planning indicated the alleged offenders were prepared to inflict a sustained attack on military personnel until they themselves were killed."
Holsworthy Barracks on the outskirts of Sydney was one of the group's potential targets, and surveillance had been carried out on others in Victoria state, he said.
Negus said the investigation also found that some Australian citizens had traveled to Somalia "to participate in hostilities" there, and that the group was seeking a fatwa, or Islamic religious ruling, approving their plans for the Australian attack. Negus did not say whose approval was being sought.
"This operation has disrupted an alleged terrorist attack that could have claimed many lives," he said.
Police announced later that one of the suspects had been formally charged with conspiring to prepare a terrorist act, a charge that carries a maximum penalty of life imprisonment. Rudd said other charges were likely to follow.
"As the Australian government has said consistently, there is an enduring threat from terrorism at home here in Australia as well as overseas," Rudd told reporters in the northern city of Cairns. "This is a sober reminder that the threat of terrorism to Australia continues."
He said he had been advised that "events today do not at this time warrant any change to our national counterterrorism level, which remains at medium" – the same security warning rating that has been in place in Australia since the Sept. 11, 2001, terrorist attacks in the United States.
Police sealed off several houses in Melbourne after the raids and were conducting intensive searches. Forensic officers in protective suits collected samples and searched at least one car parked in a driveway, while uniformed officers interviewed neighbors.
Australia has not suffered a terrorist attack on its home soil since the Sept. 11 attacks in the U.S. raised security threat levels worldwide. But dozens of Australians have died in terrorist attacks overseas, mostly in Indonesia including the 2002 bombings in Bali that targeted nightclubs frequented by Australians and other foreigners.
Homegrown terrorist plots have also been relatively rare. Seven men were imprisoned in the past year for involvement in a nascent plot to attack major sporting events in Australia in what prosecutors said was the country's largest terrorist conspiracy.
After the Sept. 11 attacks, Australia introduced tough new counterterrorism laws that grant police and security agencies strong surveillance and detention powers, and stiffened prison sentences for convicted terrorists. Australia does not have the death penalty.
Al-Shabaab, which conducts frequent attacks in Somalia, is seeking to overthrow the Horn of Africa nation's Western-backed government and establish an Islamic state. The group has claimed responsibility for several high-profile bombings and shootings in the Somali capital of Mogadishu, targeting Ethiopian troops and Somali government officials. It has also killed journalists and international aid workers.
The U.S. State Department's annual terrorism report in April said al-Shabaab was providing a safe haven to al-Qaida "elements" wanted for the 1998 bombings of the U.S. embassies in Kenya and Tanzania. The two groups have long been suspected of working together, but they have not announced a formal alliance. Al-Qaida has operations in North Africa, Yemen and Iraq.
Associated Press writers Kristen Gelineau and Rohan Sullivan in Sydney contributed to this report.