The IRA had split into the Provisional IRA and Official IRA in December 1969 . In 1971 , these ramped up their activity against the British Army and RUC . The first British soldier to be killed by the Provisional IRA died in February 1971 . That year , a string of tit-for-tat pub bombings began in Belfast . This came to a climax on 4 December , when the UVF bombed McGurk 's Bar , a Catholic-owned pub in Belfast . Fifteen Catholic civilians were killed and seventeen wounded . It was the UVF 's deadliest attack in Northern Ireland , and the deadliest attack in Belfast during the Troubles
bombed McGurk 's Bar
McGurk's Bar bombing
Ulster Volunteer Force