Australian police have arrested a man accused of planning a mass shooting for New Year's Eve in a crowded Melbourne square, officials said.
Ali Ali, a 20-year-old Australian-born citizen with Somali parents, is accused of trying to obtain an automatic rifle to attack the downtown Federation Square in Australia's second-largest city, Victoria State Police Deputy Commissioner Shane Patton said.
Thousands of revellers pack the square each year on New Year's Eve.
Ali is alleged to have downloaded instructions from an al-Qaida in the Arabian Peninsula website on how to launch a terrorist attack and how to use guns, Patton said.
Justice Minister Michael Keenan said police arrested four extremists last December over a similar alleged plot to attack Federal Square and other public places in Melbourne over the Christmas-New Year period. The four will stand trial next year on terrorism charges.
Keenan urged the public to continue with their usual routines over the period and expect to see a heavy police presence.
"Australians should be able to go about their business secure in the understanding that the government has worked very closely with law enforcement and other security agencies to keep them safe," Keenan told reporters.
Australia has strict gun laws and automatic weapons are banned from private ownership.
The man is the 74th suspect arrested in Australia in 31 counter-terrorism investigations since the country's terrorism threat level was elevated to "probable" in September 2014.
Ali appeared in a Melbourne court on Tuesday on charges of preparing to commit a terrorist attack and collecting documents to facilitate a terrorist act.
People convicted of those crimes in Australia face a maximum penalty of life in prison. Ali was not required to plead to the charges and did not apply to be released on bail.
Search warrants were issued on Monday at a home in a suburb where the suspect lived with his parents and siblings, at a relative's address in another suburb and at a computer business where he once had a part-time job.