LONDON (Reuters) - The head of Britains MI5 security service denied on Friday that his agency colluded in torture after a court ruling showed it knew that a detained British resident had been abused by US intelligence officers. In a rare public intervention, MI5 Director-General Jonathan Evans said criticism of the security agency could play into the hands of Britains enemies. In addition to bombs and bullets, they would use propaganda and campaigns to undermine our will and ability to confront them, he wrote in the Daily Telegraph newspaper. We would do well to maintain a fair and balanced view of events ... and avoid falling into conspiracy theory and caricature, he said. MI5, Britains domestic security and counter-intelligence agency, helps to investigate terrorist plots against Britain, where suicide bombings on the London transport system killed 52 people in 2005. The judges disclosed reports provided to MI5 by the CIA that Binyam Mohamed, an Ethiopian who has been fighting to prove he was tortured and that British authorities knew about it, had been shackled, threatened and deprived of sleep in US custody. One paragraph of the judges ruling that strongly criticized MI5 was deleted at the request of a government lawyer. Evans said he accepted criticism by an official committee that British intelligence had been slow to detect the emerging pattern of US mistreatment of detainees after the September 11 attacks on US cities. But there wasnt any similar change of practice by the British intelligence agencies. We did not practice mistreatment or torture then and do not do so now, nor do we collude in torture or encourage others to torture on our behalf, he said.