Australian counterterrorism police swoop on s
Australian counterterrorism police swoop on sReuters

An Australian Islamist terror cell planned to behead a random member of the public, as part of an unprecedented campaign of terror in the country.

Prime Minister Tony Abbot said that credible intelligence which led to the arrest of scores of terror suspects Thursday morning indicated that the beheading was one of a number of attacks they planned to carry out. In response to ongoing credible terrorist threats Australia raised its terror alert level to "high" for the first time ever.

More than 800 counter-terrorism police and Australian Security and Intelligence Organization (ASIO) officers swooped on homes in the early hours, with some of those detained believed to have links to the terror group Islamic State.

In Sydney alone, 25 arrest warrants were executed.

The greatest concern is said to come from members or sympathizers of the Islamic State (IS, also known as ISIS), including Australian citizens who traveled to fight with the group in Syria or Iraq who return to the country with intent to carry out attacks.

Dozens of Australians are believed to be fighting for IS at the moment, some of whom have appeared in English-language propaganda videos for the group. An Australian cleric, Robert "Musa" Cerantonio, is one of the most prominent cheerleaders for the "Islamic State" in the English-speaking world, and has openly encouraged Australian Muslims to join the group.

Australian Broadcasting Corp. reported that the suspects detained early Thursday morning planned to abduct a random member of the public in Syndey, and behead him on camera with the Islamic State flag in the background, mimicking the style of previous jihadi executions.

"The exhortations, quite direct exhortations, were coming from an Australian who is apparently quite senior in ISIL [another term for ISIS - ed.] to networks of support back in Australia to conduct demonstration killings here in this country," Abbott said of the intelligence which led to the arrests.

The dramatic counterterrorism operation comes ahead of a G20 finance ministers' meeting this coming weekend in northern Australia, as well as a major summit in Brisbane in mid-November. Australian officials dismissed suggestions the developments could disrupt planning for either event.