At least four people were killed and 20 others injured when a blast hit a religious procession held by Shia Muslims to mark the 9th day of Muharram, the first month of the Islamic calendar, in Pakistan\'s northwest district of Dera Ismail Khan on Saturday morning, said hospital sources. Dr. Khalid Baloch, Medical Supterintendant of District Headquarters Hospital in Dera Ismail Khan, a district lying some 300 km southwest of the country\'s capital Islamabad, confirmed that four people including two kids were killed and 20 others injured in the blast.