Australian Prime Minister Tony Abbott raised the country's terror threat level to 'high' from 'medium,' a level which indicates that the government believes a militant attack on home soil is likely, but stressed that there is no knowledge of specific attack plans.
"Last night the director general of security raised the terror threat to high, consequently today the government is raising the public awareness level to high," Prime Minister Tony Abbott said in a news conference in Melbourne.
"I want to stress that this does not mean that a terror attack is imminent. We have no specific intelligence of particular plots. What we do have is intelligence that there are people with the intent and capability to mount attacks here in Australia," he added.
The warning comes a day after U.S. President Barack Obama detailed plans to conduct a campaign against the Islamic State that includes targets in Syria and as America marks the 13th anniversary of the 9/11 attacks on the Twin Towers of the World Trade Center in 2001.
According to David Irvine, head of Australia's Security & Intelligence Organization, "rhetoric from the Middle East is encouraging more Australians to take violent action."
"We've seen a growth in accumulation of indicators that give security authorities more cause for concern," he said.
The world is on alert amid the rapid rise of the terrorist group ISIS, which has has taken over large swathes of Iraq and Syria in recent months, declaring the land it controls a "caliphate".
The group was responsible for the beheadings of American journalists Steven Sotloff and James Foley in recent weeks.