The attack involved two IRA active service units from the East Tyrone Brigade: an armed assault unit and a bomb unit. There were also several teams of IRA observers in the area. The assault team was armed with AK-47 and AR-15 rifles, while the bombing unit was to be responsible for planting and detonating a bomb. Both units were commanded by Patrick Kelly. The assault was launched on Saturday 7 December at 18:55, when the handful of RUC officers manning the base were getting ready to hand over to the next shift. In the first burst of automatic fire, the two guards at the entrance were killed: Constable George Gilliland and Reserve Constable William Clements. Constable Clements' Ruger Speed-Sixrevolver was taken by the attackers. The base was then raked with gunfire. Another three RUC officers who were inside ran out to the back of the base, where they hoped the walls might offer some cover. IRA members went into the building and took documents and weapons. The bomb was placed inside and, upon detonation, destroyed the entire base. Three officers were hurt. The republican magazine Iris described the attack as follows:
One volunteer took up a position close to the front gate. Two RUC men opened the gate and the volunteer calmly stepped forward, shooting them both dead at point blank range. Volunteers firing AK-47 and Armalite rifles moved into the barracks, raking it with gunfire. Having secured the building they planted a 100 lb bomb inside. The bomb exploded, totally destroying the building after the volunteers had withdrawn to safety.
The attack was one of the Provisional IRA's biggest during this period. Twelve days later the same IRA brigade mortared the RUC station at Castlederg badly damaging the base and injuring four people. The British Government responded by boosting British Army, especially Ulster Defence Regiment patrols, in isolated areas. Royal Engineers rebuilt the base in 1986. The East Tyrone IRA launched two similar attacks in the following years: the successful attack on the Birches base in 1986, and the ill-fated attack on the Loughgall base in 1987, in which eight IRA members were killed. Ballygawley itself had seen conflict before with the Ballygawley land mine attack in 1983, and would see more violence in 1988 with the Ballygawley bus bombing. The gun taken from Constable Clements was found by security forces after the SAS ambush at Loughgall. The RUC base at Ballygawley was once again targeted and wrecked for good by the East Tyrone Brigade on 7 December 1992, this time hit by the brand new Mark-15 improvised mortar, better known as "Barrack Buster". Three RUC constables were wounded. The station was never rebuilt.
