Syrian regime used toxic weapons: report

Australia has joined the world in condemning Syrian President Bashar al-Assad after an international investigation found his rogue regime used chemical weapons against civilians.

The latest report by the Organisation for the Prohibition of Chemical Weapons has confirmed that a toxic chemical, most likely chlorine, was "systemically and repeatedly" used during the long-running conflict.

The global chemical weapons watchdog obtained evidence showing helicopters used by the Syrian regime dropping their deadly payload on civilian centres in the north of the country last year.

Foreign Minister Julie Bishop said this "brutality" against civilians violated United Nations law and the Chemical Weapons Convention, to which Syria agreed to comply with in October 2013.

"The Australian government is deeply disturbed by these findings," Ms Bishop said in a statement on Saturday.

"I have no doubt that the Syrian regime was responsible for these attacks."

The UN Security Council unanimously passed a landmark resolution in September last year to eradicate Syria's chemical weapons arsenal after prolonged negotiations between the United States and Russia.

It was the first time since the conflict began in March 2011 that the council has agreed to place any legally binding obligations on Syria.

Australia has since provided $2 million toward the destruction of Syria's chemical stockpile.

President al-Assad and the Syrian rebels trying to overthrow his regime have both accused each other of using chemical weapons during the deadly civil war.