SYDNEY(National Times)- Counter-terrorism forces arrested two women for slavery on Thursday as they returned to Australia from Syria, where they allegedly committed “crimes against humanity” while supporting the militant Islamic State group.

The women and their children — all Australian citizens — landed on Thursday evening after years spent in a Syrian detention camp where they have languished since the group’s demise. Police arrested the women immediately after they landed at Melbourne international airport.

They were among four women and nine children returning to Australia for the first time after allegedly sneaking into Syria to join the IS group’s self-declared caliphate in the early 2010s.

Australian Federal Police counter-terrorism boss Stephen Nutt said a 53-year-old woman was accused of a raft of “crimes against humanity”, including possessing a slave, using a slave, and slave trading. A 31-year-old woman faced two slavery charges, Nutt said.

“The women will appear before a court once they have been charged,” he said. Nutt said there was little else he could say given the looming legal process, but confirmed the slavery charges allegedly took place in Syria.

“All I can say is the safety of the community is the number one priority for all agencies involved,” he told reporters. A third woman, 32, was arrested after landing in Sydney and would be charged with travelling to a banned area and joining a terrorist organisation, he said.