Updated

A 50-year-old man has been arrested at London Heathrow airport on suspicion of a terrorism offense.

British police say the man was taken into custody by counter-terrorism officers after arriving in Britain on a flight from Cairo on Wednesday.

He was arrested on suspicion of possessing articles which contained information likely to be useful to a person planning an act of terrorism.

A property in north London was being searched as part of the investigation.

Police have said that the arrest was pre-planned and not related to the Islamic State group or the conflict in Syria.

Mounting concern over the possibility of an extremist attack in Britain has led to increased airport security and increased checks of passengers on incoming flights from the Middle East.