Australia on Friday said France, Germany and Japan were potential partners to design and build its next generation of submarines, in what will be its biggest ever defense procurement program.

As Canberra seeks to replace its ageing Collins Class fleet, Defense Minister Kevin Andrews said all three countries had proven military design and build capabilities and were currently producing submarines.

Australia returned four Sri Lankan asylum-seekers approaching the nation's waters by boat, Immigration Minister Peter Dutton said Thursday, three weeks after the government secured a major legal victory for its tough immigration policy.

Customs officers intercepted the boat northwest of the remote atoll of Cocos Islands in the Indian Ocean on February 9, Dutton said in a statement.

Some 15 asylum seekers hoping to make it to Australia and detained in Papua New Guinea have sewn their lips together and 400 are on hunger strike, a report said Thursday.

A spokesman for Australian Immigration Minister Peter Dutton did not comment on the scale of the protest, while conceding that some asylum seekers at a detention center had harmed themselves. He insisted that the protest was "peaceful."

Two men have been arrested after counter-terrorism raids in Sydney, Australian officials said Saturday, following long-running investigations into those backing fighters involved in conflicts such as in Syria and Iraq.

Officers arrested one man on Friday following raids at four properties in Sydney's southwest that police said were "part of a long-running investigation and not as a result of any specific terrorism threat".

Australian police late Thursday searched several properties across Sydney, reportedly as part of a ongoing counter-terrorism investigation but not related to the deadly cafe siege earlier this week, officials said.

New South Wales police said the raids were unconnected to the 16-hour standoff at a Sydney cafe on Monday that left the lone gunman, self-styled Islamic cleric Man Haron Monis, and two hostages dead, but would not provide further details about the operation.

A man has been arrested in Sydney on alleged terrorism offences as part of ongoing investigations into plans for an attack on Australian soil, police said Monday. 

The 25-year-old was seized as part of "continuing investigations into the planning of a terrorist attack on Australian soil and the facilitation of travel of Australian citizens to Syria to engage in armed combat".

The Australian government failed in its duty to protect asylum-seekers at a camp in Papua New Guinea where a February riot left one dead and 69 injured, said a damning parliamentary report released Thursday.

Iranian Reza Barati was killed in the riot at the Manus Island detention center in February as tensions flared among inmates about their fate under Australia's hardline asylum-seeker policies.

Maronite Patriarch Beshara al-Rahi stressed on Tuesday the importance of equality between Muslims and Christians in Lebanon, reiterating that the fighters of the Islamic State of Iraq and the Levant (ISIL) are not linked to Islam.

“Lebanon is a model for coexistence between Muslim and Christian. They both live equally,” al-Rahi said from the Australian capital Canberra.

Police have shot dead a "known terror suspect" who stabbed two officers, a day after the Islamic State group called for Muslims to indiscriminately kill Australians, officials said Wednesday.

The 18-year-old, reportedly associated with the Islamic group Al-Furqan, was killed on Tuesday evening, having arrived at a police station on the outskirts of Melbourne to attend a "routine" interview.

Australian's foreign minister met Arab and Islamic ambassadors Thursday to try to soothe concerns over Canberra's stance on East Jerusalem, insisting there was no policy change despite moves to stop referring to it as "occupied".

The meeting followed fury after Attorney-General George Brandis said the term would not be used as it carried pejorative implications and was neither appropriate nor useful.