SYDNEY: Australian counter-terrorism police shot dead a man who was under surveillance, with the Australian Broadcasting Corp. reporting he allegedly made threats against Prime Minister Tony Abbott.

The 18-year-old man was shot late Tuesday after stabbing two officers outside a police station in southeast Melbourne, where he was due to be interviewed as part of an investigation, authorities said. Intelligence indicated the man had been seen waving an Islamic State flag, Australian Federal Police Commander Bruce Giles told reporters in a midnight briefing, without elaborating.

“The information that we have at the moment is that the individual was acting alone,” said Giles, who didn’t comment on reports the man had made threats against Abbott.

Australia raised its terrorism alert to the highest level in a decade this month, citing the threat posed by supporters of Islamic State extremists. Last week, authorities said police foiled an alleged Islamic State beheading plot after carrying out the nation’s largest ever anti-terrorism raid.

Abbott’s government says 60 Australian citizens are fighting with Islamic State in Iraq or Syria and 20 fighters have returned from conflict zones. The government plans legislation to curb people traveling abroad to areas where the militant group is active and has been canceling passports.

Onlookers who witnessed the incident said the man had been shouting insults about Abbott and the Australian government in the moments before he was shot, the Age newspaper reported. Police had recently canceled the man’s passport, the ABC said. The two stabbed officers were from the Joint Counter Terrorism Taskforce and were taken to the hospital in a stable condition, Victoria state police said in a statement.

The state’s Assistant Commissioner Luke Cornelius told reporters he wasn’t in a position to comment on what had motivated the man to attack the officers.