Police have erected a 3-meter-high concrete wall and tightened security in a Christian district of Karachi after two people were killed in attacks by Muslim Pashtuns angry at the video ridiculing the Prophet Mohammad. The barrier, which crosses all the major arteries in and out of the Christian slum of Essa Nagri, has effectively sealed the area off after gunmen opened fire on a Christian funeral service on Saturday. “They left chanting more deaths to Christians,” said Saleem Bhatti, who was one of four people injured when he received a gunshot wound to the leg. Hundreds of Christian mourners yesterday demanded government protection as they blocked the road leading to the graveyard where the shootings took place.