Rival anti-Islam and anti-racism rallies saw hundreds protest across Australia at the weekend with violent clashes in Melbourne, as police officers mounted a strong presence in cities Sunday to keep the two sides apart.

About 100 anti-Islam protesters from the Reclaim Australia and United Patriots Front groups waved the national flag and yelled chants at a rally in Sydney Sunday, with signs declaring "Say no to Sharia" and "Immigration is the elephant in the room".

An Australian man who consented to an Islamic "marriage" ceremony between his 12-year-old daughter and a Lebanese man more than twice her age was Friday jailed for at least six years.

The 63-year-old father, who cannot be named to protect the girl's identity, was found guilty in April of procuring a child under the age of 14 for unlawful sexual activity and encouraging the pair to have intercourse despite denying the charges.

Populations of some of Australia's iconic birds -- including the laughing kookaburra, magpie and willie wagtail -- are in decline in parts of the country, according to a report released Wednesday, with habitat loss, feral cats and foxes among the likely threats.

The State of Australia's Birds report, published by Birdlife Australia, was compiled using data from 420,000 surveys collected by volunteers across the continent since 1998. 

A Serbian war crimes suspect nicknamed "Captain Dragan" arrived in Zagreb on Thursday from Australia to face allegations of torture and murder after battling extradition for a decade.

"After a long battle, which started nine years ago, Dragan Vasiljković was extradited ... and is now in Croatia," Justice Minister Orsat Miljenić told reporters.

Heavily-armed police quelled a riot involving up to 300 inmates at an Australian jail Wednesday over the introduction of a smoking ban, with a handful of prisoners injured.

Melbourne's Metropolitan Remand Center remains in lockdown after the 15-hour disturbance when doors were smashed, fires lit and some inmates armed themselves with sticks and iron bars from the jail's agricultural sheds.

An Australian man has died after stepping on a landmine in Syria while fighting for Kurdish forces against the Islamic State group, his family said Wednesday.

Keith Harding said he learned on Monday that his 23-year-old son Reece, who left Australia in May, died on the weekend during a night-time operation.

Australian Prime Minister Tony Abbott on Monday urged countries around the world to proactively help fight the Islamic State (IS) group instead of expecting others to do the "heavy-lifting", as the jihadists eye international expansion.

Speaking at a public lecture on regional security in Singapore, Abbott said the group, which has drawn thousands of people worldwide to fight in Syria and Iraq, could commit "more and worse atrocities as long as even a small minority of people are susceptible to its message."

The mother-in-law of a notorious Lebanese-Australian Islamic State group fighter said Monday she was "devastated" that police had refused to help bring her five grandchildren home from Syria.

Karen Nettleton's daughter Tara is married to Khaled Sharrouf, who gained global infamy last year when he posted pictures of himself and his seven-year-old son on Twitter holding up the severed heads of soldiers.

Canberra was Sunday attempting to verify whether an Australian Islamic State group fighter, notorious for being photographed with severed heads, had survived a drone attack after a report said he was still alive.

Australian media last week reported that two of the country's most wanted IS jihadists, Khaled Sharrouf and Mohamed Elomar, were believed killed in a drone strike in Syria.

Australia's domestic spy agency Thursday played down concerns that maps shown in a media briefing revealing the source of homegrown fighters travelling to the Middle East were classified, after fears their publication was a security breach.

The maps, which revealed the Sydney and Melbourne suburbs where fighters heading to join jihadists came from, were photographed and filmed by journalists during a meeting Wednesday between Prime Minister Tony Abbott and spy chief Duncan Lewis.