After a five-month campaign parents at the St Brigid primary in Crossmaglen, Co Armagh, have persuaded Ulster’s Environment Department to monitor the flights.

Activity at the army look-out post half a mile from St Brigid’s became an issue in May when parents said helicopters were flying low over the school. They claimed the noise disrupted lessons and that pupils faced a radiation threat from surveillance equipment.

Last week teachers agreed to record how often helicopters flew over and the environment department is to monitor the noise.

Parents also last week enlisted the support of two Dublin-based human rights activists. Campaigners Majella Carron and Catherine Ferguson will compile a report on the flights over the school and the use of surveillance equipment.

Crossmaglen is a nationalist stronghold where the presence of army look-out posts has long been a cause of rancour.

The army has said that it goes to “great lengths” to avoid disturbance to schools where possible.