during the course of fierce riots in nationalist areas triggered by the Drumcree conflict, the total number of security forces in Northern Ireland increased to more than 30,000 (including the RUC). Equipment Vehicles used by the British military during Operation Banner, some of which were developed for the operation, include: Alvis Saracen Alvis Saladin Ferret armoured car Humber Pig Saxon Land Rovers, including the Snatch Land Rover Aérospatiale Gazelle helicopter Aérospatiale SA 330 Puma helicopter Chinook helicopter Westland Lynx helicopter Controversies The British military was responsible for about 10% of all deaths in the conflict. According to one study, the British military killed 306 people during Operation Banner, 156 (~51%) of whom were unarmed civilians. Another study says the British military killed 301 people, 160 (~53%) of whom were unarmed civilians. Of the civilians killed, 61 were children. Only four soldiers were convicted of murder while on duty in Northern Ireland. All were released after serving two or three years of life sentences and allowed to rejoin the Army. Senior Army officers privately lobbied successive Attorneys General not to prosecute soldiers, and the Committee on the Administration of Justice says there is evidence soldiers were given some level of immunity from prosecution. Elements of the British Army also colluded with illegal loyalist paramilitaries responsible for numerous attacks on civilians (see below). Journalist Fintan O'Toole argues that "both militarily and ideologically, the Army was a player, not a referee". Relationship with the Catholic community Many Catholics initially welcomed the British Army's deployment, as Catholic neighbourhoods had been attacked by Protestant loyalists and the RUC. However, relations soured between the British Army and Catholics. The British Army's actions in support of the RUC and the unionist government "gradually earned it a reputation of bias" in favour of Protestants and unionists. In the British Army's campaign against the IRA, Catholic areas were frequently subjected to house raids, checkpoints, patrols and curfews that Protestant areas avoided. There were frequent claims of soldiers physically and verbally abusing Catholics during these searches. In some neighbourhoods, clashes between Catholic residents and British troops became a regular occurrence. In April 1970, Ian Freeland, the British Army's overall commander in Northern Ireland, announced that anyone throwing petrol bombs would be shot dead if they did not heed a warning from soldiers. The Falls Curfew in July 1970 was a major blow to relations between the British Army and Catholics.