Four members of the 6th Battalion The Ulster Defence Regiment, Private Oswell Neely, Private Thomas Harron, Private Ronald Alexander and Private John Roxborough, were killed by a 600lb landmine at Drumquin in County Tyrone, Northern Ireland.

They were in the last Land Rover of a five-vehicle convoy en route to Ballykinler from Omagh. The device left a crater 40 feet wide and 15 feet deep. This was the greatest lost of life in a single incident since the raising of the UDR; it remained so until the killing of another four soldiers in 1990.