Seven Pakistani Christians were shot dead in the centre of Karachi today. The group, who worked for the Institute for Peace and Justice were tied up and shot by two unidentified gunmen in their third floor office. Another person who survived the shooting is in a critical condition. The Institute is a non-political charity working with the city's poorest people. The Catholic Archbishop of Karachi Simeon Pereira said in a BBC interview that the latest attacks would raise fears within the Christian community of further violence. He said: "I have heard reports that extremist groups plan to carry out attacks against Christian institutions within the next 20 days. "We have police posted outside our churches day and night. The Christian community is not panicking at the moment, but I don't know what will happen as a result of the latest killings - people will suspect it was a terrorist attack." The archbishop said Christians were identified with "foreign powers", although most of the priests were local. Christian schools and institutions will be closed for the next three days and a march is planned to the United Nations building in Islamabad.