SYDNEY (Reuters) - Australian counter-terrorism police were conducting raids across several Sydney suburbs late on Saturday.
Australian Federal Police (AFP) said the "operational activity" by the Sydney Joint Counter Terrorism Team "relates to an ongoing investigation."
"The safety of the community and police members are the primary consideration during this activity," the AFP said in a press release, declining to provide further information as the raids were still in progress.
The raids were being carried out in four suburbs in different parts of the city, police said.
Australia, a staunch ally of the United States, has been on heightened alert for attacks by home-grown militants returning from fighting in the Middle East, or their supporters, since 2014.
Authorities say they have thwarted a number of potential attacks since then, but there have been several "lone wolf" assaults, including a cafe siege in Sydney that left two hostages and the gunman dead.
About 100 people have left Australia for Syria to fight alongside organizations such as Islamic State, Australia's Immigration Minister said last month.
Australian newspaper publisher News Ltd reported up to 40 riot squad officers were seen swooping on a house in the inner city suburb of Surry Hills.
(Reporting By Jane Wardell; Editing by Christian Schmollinger)