MELBOURNE (AP) ― Counterterrorism police launched early morning raids on Tuesday in homes across several suburbs in the Australian city of Melbourne, where a suspected terrorist was shot dead last week.

A joint state and federal police operation supported by surveillance helicopters executed search warrants in the suburbs of Seabrook, Kealba, Meadow Heights, Broadmeadows and Flemington, Australian Federal Police and state Victoria Police said in a statement.

Australian Broadcasting Corp. reported a man had been handcuffed and taken into custody at Seabrook. Police would not immediately confirm any arrests.

Victorian Premier Denis Napthine said he was briefed by police as the raids started and was told they were part of a long-running and ongoing counterterrorism operation.

“They are not about a specific threat. ... There is certainly no immediate concern for public safety,” Napthine told Fairfax radio in Melbourne. “It’s a sad situation that we now face.”

Police said the raids in Australia’s second-largest city were not a response to a threat to public safety or related to last week’s shooting.

Numan Haider, 18, was killed last Tuesday after he stabbed two police officers during a routine meeting outside a Melbourne police station. Both officers are recovering.

Prime Minister Tony Abbott said the knife attack was inspired by the Islamic State group.

Two weeks ago, police detained 16 people in counterterrorism raids in Sydney and charged one with conspiring with an Islamic State leader in Syria to behead a random person. Small-scale raids continued in that city for days afterward in what police described as an ongoing investigation.

Earlier this month, Australia raised its terror warning to the second-highest level, citing the domestic threat posed by Islamic State supporters.