Two men carrying Tula-Tokhrev combat pistols barged into the offices of the Idara-e-Amn-o-Insaf, an ecumenical body, at 10:30 a.m. and made the workers their prisoners. According to a police official, the charity workers were first gagged and bound with rope and then shot. "They died from bullet wounds to the head," a policeman said. "They could not escape from their attackers' clutches," he added. Some months ago a senior member of the charity, Ivan Edwin, was bound with rope and given a lethal injection. Eyewitnesses said the assailants were clean-shaven and clad in standard trousers and shirts and not shalwar kameez suits--earlier worn by assailants who attacked two Christian targets in northern Pakistan last month. But it is not clear how the armed men managed to reach the charity's office on the third-floor of the 13-storey Rimpa Plaza building without detection. Most of the offices in the building operate under tight security and visitors entry is restricted. The measures were taken after a spate of robberies in the late '90s. Asad Jehangir, a senior police official, confirmed this afternoon that six Christians had been killed in the attack following his visit to the building, which has since been cordoned off. Jehangir identified the slain men as Mushtaq Roshan, Aslam Martin, John Menezes, Kamran Anjum, Iqbal Allahrakha and Benjamin Talib. Martin was the project coordinator of the Idara-e-Amn-o- Insaf. The injured men were identified as Edwin Foster and Robin Piranditta. According to policemen, they were badly beaten up but not shot by the assailants. Police suspect Wednesday's attack was carried out by religious extremists angered by the government decision last year to back the United States in its war against terror. The attack came within 24 hours of the arrest of two Lashkar-e-Jhangvi activists who supplied hand-grenades to the men who stormed a chapel in Taxila and killed five nurses on August 9. Last week the city police found maps of two Karachi churches and a missionary school in the possession of militants that it arrested. The school was identified as the Christ Church missionary school in Cantt Bazaar, Drigh Colony. The church-sponsored Idara-e-Amn-o-Insaaf is a non-governmental organisation that has for the past 30 years undertaken welfare projects in the city and campaigned for social justice.