Seven young Australians have been stopped on their way to join terrorists in the Middle East, ABC quoted Australian Prime Minister Tony Abbott as saying on Thursday.

"We have stopped at the airport seven young Australians who were planning to travel to the Middle East, it seems, to join terrorist groups over there," Abbott said.

Immigration Minister Peter Dutton confirmed an incident at Sydney International Airport on August 12, which is believed to be when five Australians were stopped.

"That follows a number of people who have been off-loaded by the counter-terrorism unit officers, in particular in Sydney and Melbourne, over a period of time," Dutton said.