Federal police are to take over security at Australia's parliament, Prime Minister Tony Abbott said Friday, describing the building as a potential terror target, following revelations that Islamic State jihadists were plotting "demonstration executions".

"Parliament House certainly is a potential target," Abbott said.

Four assailants in a vehicle bearing the flag of the Islamic State of Iraq and the Levant (ISIL) drove past the Maronite Our Lady of Lebanon Church in Sydney, shouting death threats to church-goers, media reports said on Thursday.

“Four youth in an unknown car and waving the flag of ISIL drove by the church threatening church-goers with murder and with slaughtering their children,” the parish custodian, Monseigneur Shora Maree, revealed.

Australia's largest ever counter-terrorism raids on Thursday detained 15 people and foiled a plot by Islamic State jihadists to conduct "demonstration killings", reportedly including beheading a member of the public on camera.

Prime Minister Tony Abbott said Sunday Australia would deploy 600 troops to the United Arab Emirates to join the U.S.-led international coalition gearing up for war against Islamic State jihadists.

Abbott's announcement comes two days after Canberra lifted its terror alert level to "high" on growing concern about Australian jihadists returning from fighting in Iraq and Syria.

Dutch prosecutors said Friday they need to know where a missile that may have shot down flight MH17 was fired from in eastern Ukraine before criminal charges could be laid.

The Australian government on Friday elevated its terrorism threat level to the second-highest warning in response to the domestic threat posed by Islamic State movement supporters.

Prime Minister Tony Abbott announced the increase from "medium" to "high" on a four-tier scale on the advice of the Australian Security Intelligence Organization.

Australian police apologized Thursday after a suitcase with plastic explosives inside used for sniffer dog training was left at Sydney airport and only found four weeks later by a passenger.

The woman, travelling through the country's busiest airport on Tuesday, was given the unclaimed bag as a replacement after her one was damaged during a flight.

Two men charged in Australia with allegedly recruiting, funding and sending jihadist fighters to Syria faced court Thursday as Prime Minister Tony Abbott announced new measures to stem terrorism financing.

Omar Succarieh, 31, and Agim Kruezi, 21, appeared in a Brisbane court after their arrests in anti-terrorism raids on Wednesday following a year-long police investigation.

Pounding the streets of Edinburgh, campaigners for Scottish independence are more hopeful than ever that they can win next week's referendum -- and a last-minute visit by British Prime Minister David Cameron cannot dampen their enthusiasm.

The atmosphere in the Scottish capital is electric as a sharp narrowing of opinion polls has made the prospect of the break-up of the United Kingdom a distinct possibility in the September 18 vote.

Australian police Wednesday raided an Islamic centre and seized two men for alleged involvement in recruiting and sending jihadist fighters to Syria.