Internment had been used several times in Ireland during the 20th century, but had not previously been used during the Troubles, which began in the late 1960s. Ulster loyalist paramilitaries, such as the Ulster Volunteer Force (UVF), had been engaged in a low-level violent campaign since 1966. After the August 1969 riots, the British Army was deployed on the streets to bolster the police, the Royal Ulster Constabulary (RUC). Up until this point, the Irish Republican Army (IRA) had been largely inactive. However, as the violence worsened, the IRA was divided over how to deal with it. It split into two factions, the Provisional IRA and Official IRA. In 1970–71, the Provisionals began a guerrilla campaign against the British Army and the RUC. The Officials' policy was more defensive. During 1970–71, there were numerous clashes between state forces and the two wings of the IRA, and between the IRAs and loyalists. Most loyalist attacks were directed against Catholic civilians, but they also clashed with state forces and the IRA on a number of occasions.