Armed policemen were on guard outside Christ Church, in the heart of Rawalpindi's garrison area, as worshippers arrived for the 10.30am service yesterday.
"We are afraid," said a teacher who would not give his name. "Since this talk of a war between Christians and Muslims began, we feel like a target."
Built by the British Raj, the Victorian Gothic church is full of monuments to the likes of Lieutenant A R Murray of the Bengal Lancers, who served with distinction in the Afghan War of 1878-79 before dying of cholera at the age of 24. It is now attended by about 1,400 mainly middle-class members of the Church of Pakistan, part of the Anglican communion.
Pakistan's tiny Christian minority – about 4 million in a country of 140 million – has never felt entirely secure. With a new Afghan war looming since the attacks on the World Trade Centre and the Pentagon, the Christians are beset with fears and rumours.
As they sheltered under awnings from the hot sun after the service at Christ Church, parishioners exchanged tales of public bible-burnings and the alleged murder of a Christian boy in a slum on the other side of the city.
"One incident could start everything," said Fr John Nevin, an Irishman who had just said mass in fluent Urdu at Fatima Catholic Church in Islamabad. "We heard that a mullah in Rawalpindi was warned by the police after telling his followers that for every Muslim killed in Afghanistan, they should pick off two Christians here."
Although Pakistan's constitution guarantees religious freedom, there is a steady stream of attacks on Christians by Muslim zealots, usually in the poor areas of Punjab where the country's Christians are concentrated.
The Catholic bishop of Faisalabad, John Joseph, publicly committed suicide in 1988 to protest against a blasphemy law under which several Christians have been condemned to death. Although the verdicts were overturned on appeal, Christians charged with blasphemy against Islam have been murdered by fundamentalists before their cases reached the courts, and a judge in Lahore who overturned a conviction was assassinated.
Pakistan's President, General Pervez Musharraf, proposed amending the law last year, but backed off when Muslim groups threatened protests.
In Rawalpindi, members of Christ Church's congregation recalled that the Presentation Convent, a stone's throw away, was burnt to the ground in the 1970s after the Kaaba in Mecca, Islam's holiest shrine, was attacked, even though the perpetrators turned out to be Muslim extremists.
"My message to the West is this," said the pastor of Christ Church, the Rev Emmanuel Lorraine. "Please do not make revenge attacks on Muslim minorities in your countries, because whatever happens there will come on our heads, two- or three-fold. I heard that a mosque was burnt in Australia. This is not good for us. Our people are scattered, living among the Muslims."
One of his parishioners said: "The police protect us here, but they cannot protect our homes."
Most of Pakistan's Christians are far poorer than those who attend Christ Church. In Phagwari, a slum a few miles away, worshippers were sitting on the ground in the midst of a roofless ruin as their pastor, known only as Qamar, expounded from the Bible.
Buffaloes were being herded past to drink from a filthy river at the bottom of a 30ft gully. The only sign that this was a Christian gathering was a red cross painted on a partially collapsed wall.
Naeem, a members of Qamar's Independent Church, said the church had been destroyed by devastating floods a month or two ago which had swept away hundreds of people in this part of Rawalpindi. "About 1,000 Christians live here, but most of us have no work except as day labourers," he said. "People live 14 or 15 to a room. We can't afford to rebuild our church."
But Naeem said relations with local Muslims had not deteriorated. "There are sometimes fights, but the police protect us. Everybody around here is poor, Christian or Muslim. We have the same problems."
The Right Reverend Alexander John Malik, Bishop of Lahore, the head of the Church of Pakistan, said he had written to the authorities to seek protection for Christians and their institutions. "The government is very aware of the danger," Dr Malik said. "There is tension, and people are fearful, but so far there have been no incidents. We have to pray that nothing will happen, but we must also pray that the Americans will take no hasty steps. If they do, we will suffer."Reuse content