About 500 Pakistani Christians in Charsadda, a town in the North West Frontier Province bordering Afghanistan, received letters earlier this month telling them to close their churches and convert by Thursday or be the target of "bomb explosions."
Several Christians, a tiny minority in the predominantly Muslim country, have fled the town and others are living in fear, community leaders said. Some complained that police were not taking the threat seriously.
"Police say someone is joking with us by writing these letters," Chaudhry Salim, a Charsadda Christian leader, said during a news conference in Islamabad. "They have deployed only two policemen at our churches ... this is the kind of security we are getting now."
Shahbaz Bhatti, a prominent Christian leader and head of the All Pakistan Minorities Alliance, said the provincial government, which is controlled by a coalition of pro-Taliban religious parties, would bear blame for attacks after the deadline.
Bhatti also urged Muslim religious scholars to condemn the threats and said the federal government should take "concrete steps to provide protection" to Christians.
Asif Daudzai, a spokesman for the provincial government, asked Christians not to panic, saying authorities were doing all they could to ensure their protection.
"Christians are our brothers and sisters, and we will not allow any one to harm them," he told The Associated Press.
Christians, Hindus, Sikhs and other religious minorities make up about 3 percent of Pakistan's 160 million residents.
Most live peacefully alongside the Muslim majority, although the groups have been targeted repeatedly in attacks blamed on extremists since the country allied itself with the United States after the Sept. 11, 2001, attacks.
Islamic radicals trying to impose Taliban-style social edicts in northwestern Pakistan are growing bolder, bombing shops selling Western films, threatening barbers for trimming beards and warning hotels to remove televisions from guest rooms.
Minorities and secular opposition parties say the government is doing too little to counter the "Talibanization" of growing swaths of the country.