On the evening of 26 March 1997, the Provisional IRA East Tyrone Brigade launched an improvised grenade attack on the fortified Royal Ulster Constabulary/British Army base in Coalisland, County Tyrone, Northern Ireland. The blast sparked an immediate reaction by an undercover Special Air Service unit, who shot and wounded Gareth Doris, an Irish republican and alleged IRA volunteer. The SAS unit was then surrounded by a crowd of protesters who prevented them approaching Doris or leaving. RUC officers arrived and fired plastic bullets at the crowd, allowing the special forces to leave the area.