Five men who allegedly planned to travel by boat to Indonesia so they could join Islamic State in Syria have arrived in Melbourne after being extradited from Cairns under tight security.

Islamic preacher Robert "Musa" Cerantonio, Shayden Thorne, Kadir Kaya, Paul Dacre and Anthony Granata will appear before a Melbourne magistrate on terrorism-related charges after they touch down.

A Cairns magistrate approved their extradition on Monday and AFP officers are escorting the men to their flight on an Australian Border Force aircraft, which left Cairns about 6:40am.

The men have been charged with making preparations for incursions into foreign countries to engage in hostile activities.

They face a maximum penalty of life in jail if found guilty.

The men - who are all from Melbourne and aged between 21 and 31 — were arrested on remote Cape York last Tuesday.

Police allege they had towed a seven-metre boat from Melbourne, and planned to go to West Papua, then the Philippines, then on to Syria to join IS.