SYDNEY, The Australian authorities have arrested a 27-year-old man on Thursday for allegedly attempting to join the conflict in Syria and Iraq between April and June this year as part of a long running investigation into travelling and returned foreign fighters.

Australia, a staunch ally in the U.S.-led fight against terror in Syria and Iraq, has remained on heightened alert for home-grown terror attacks for over two years, arresting or jailing at least 45 suspects in connection to domestic terror plots.

The Authorities fear those who have travelled to and returned from Syria, Iraq or any other area where hostile activities are occurring, would become more radicalized and bring back a greater capability in the use of weapons and explosives for any potential attack on Australian soil.

Recent attacks in Europe where trucks have crashed into large gatherings are only heightening fears.

"Police have constantly warned people against travelling to conflict zones, and we again want to emphasise that actively making plans to join groups in those areas is a criminal offence," Australian Federal Police acting assistant commissioner for counter terrorism Jennifer Hurst said in a statement on Thursday.

"The challenge in these matters is to obtain evidence to an appropriate standard for prosecution, but we will work cooperatively and diligently to act in response to those who choose to follow an extremist ideology that is not compatible with the diverse, inclusive values of the Australian community."

The Australian government forbids any Australian traveling to war zones without special permission, and those who do and join either side of the conflict face harsh penalties.

Under controversial foreign fighter laws, any dual national will have their Australian citizenship revoked if they are alleged to be a member of an organization listed on Australia's official terror group watch list.

The 27-year-old arrested in Western Sydney on Thursday, charged with one count of making preparations for incursions into foreign countries for purpose of engaging in hostile activities, faces life imprisonment.

Investigations are also ongoing into Australians who have fought for forces battling Islamic State such as the Syrian-Kurdish militant group YPG.