Profilers have been operating at Paris's Charles de Gaulle airport since the attacks on Brussels airport, its operators revealed on Thursday.

They have been watching for “abnormal behaviour” at France's biggest airport, Aeroports de Paris (ADP) said.

Among other extra security measures, a facial recognition system will be tested in the next few months.

Instead of passengers having to place their finger on a screen to be identified, the system will immediately recognize their face.

“If a person poses any problems… an alert will automatically be sent to the police who will come and question them,” ADP chief executive Augustin de Romanet said.

He said Paris airport authorities were working with police to double the number of automatic security checks of passengers in the next three years.

The number of security cameras has been increased in areas of the airport “where we need to be able to keep a closer eye on the comings and goings”, he said.

Suicide bombers detonated their explosives in the check-in area of Brussels airport on March 22nd and at a metro station, killing a total of 32 people.

Like the Paris attacks in November which killed 130 people, those in Brussels were claimed by the Islamic State group.