Specialised Australian Border Force counter-terrorism teams have helped offload more than 300 passengers at Australia's main international airports since they began operations last year.

The force has counter-terrorism unit (CTU) officers based at eight international terminals; Sydney, Melbourne, Brisbane, Perth, Cairns, Gold Coast, Adelaide and Darwin.

Airport counter-terrorism units In 2014–2015 financial year Australian Border Force officers: assisted in 336 passenger offloads

assisted in 336 passenger offloads conducted 133,368 real-time assessments

conducted 133,368 real-time assessments conducted 9,201 patrols

After initially being deployed at Sydney and Melbourne airports in August 2014, they have now conducted around 135,000 real-time assessments of travellers across the country.

The 2014-2015 annual report of the now defunct Australian Customs and Border Protection Service — which was merged this year into the new Australian Border Force — reveals the teams assisted in 336 passenger offloads up until the end of June 2015.

The document said the CTU had intercepted a "number of people of national security concern" including "preventing a number of minors from travelling to the conflict areas in Syria and Iraq".

"Upon examination of persons of concern, the CTU teams have found evidence of significant movements or attempted movements of large sums of cash, and images and material of an extremist nature," the report said.

"Some cases have resulted in the imposition of infringement notices, while others are the subject of ongoing investigations."

From 2015, CTU officers have been exempt under the Aviation Transport Security Act 2004 from airport security screening and permitted to carry firearms in an airport.

Last financial year 67 passports were cancelled by the Federal Government on security grounds, up from 45 the year before.

In the past three months at least 20 passports have been cancelled.