AUSTRALIA announced plans today to regulate travel to certain countries in a raft of measures aimed at addressing possible domestic threats from war-hardened homegrown jihadists.

“What we are determined to do is to ensure that, where people have been involved in terrorist activities, it is much more readily possible to secure convictions than it currently is, given the difficulty of getting evidence of exactly what might be happening overseas,” said Tory Prime Minister Tony Abbott.

But he cautioned: “We don’t want to subvert Australian justice. The last thing any of us would choose to do is to defend our system by damaging our system.”

Mr Abbott said it was difficult to find witnesses to testify in Australian courts to atrocities in foreign war zones that are often posted on social media websites.

“We’ve all seen truly shocking imagery of Australians born and bred doing absolutely horrific things to surrendering Iraqi police and military personnel,” he said.

Police announced arrest warrants last week for two Australians fighting with the Islamic State group after one posted photographs of the other posing with Syrian soldiers’ severed heads. 

Former Sydney residents Khaled Sharrouf and Mohamed Elomar would be arrested if they return to Australia, police said.

Under legislation prepared for parliament, it would become a criminal offence to travel to designated countries “without a valid reason.”

Attorney General George Brandis said that the onus would be on someone who travels to such a country to explain that the reason was humanitarian, family or for “other innocuous purposes.”