SYDNEY (AP) -- Police raided properties in several Sydney suburbs and arrested four men on Saturday on suspicion of plotting a terrorist attack, officials said.
The raids related to a bomb plot involving aircraft, Fairfax Media, News Corp. and the Australian Broadcasting Corp. reported.
Prime Minister Malcolm Turnbull said the counterterrorism raids on Saturday afternoon were "designed to disrupt and prevent plans to undertake terrorist attacks in Australia."
The operation was carried out by the Australian Federal Police, the New South Wales state police and the Australian Security Intelligence Organisation, the country's domestic spy agency.
"Four men have been taken into custody and are assisting police with their enquiries," a police statement said.
Seven Network television reported that 40 riot squad officers stormed an inner-Sydney house before an explosives team found a suspicious device.
Turnbull said he was briefed on the progress of the operation by security agency heads.
"My number one priority, and that of my government, is the safety and security of all Australians, and the public should be reassured that our security and intelligence agencies are working tirelessly to keep us safe," the prime minister said in a statement.
Turnbull is expected to provide further details on Sunday.