Pakistani authorities have sent police and army reinforcements to the city of Bahawalpur after an attack in a Christian church that killed up to 18 people Sunday.
Gunmen shouting "God is great" in Arabic opened fire in the church during regular Sunday service. Witnesses say the gunmen ignored congregants' pleas for mercy. A Protestant service was under way at the time in the Roman Catholic-owned church.
Hours later, an explosion wrecked a bus in Quetta near the border with Afghanistan, killing at least three passengers.
No one has claimed responsibility for either attack. But Pakistani officials say members of a banned Islamic group are under suspicion for the church massacre.
Both Pope John Paul and Pakistani President Pervez Musharraf have condemned the massacre. General Musharraf blamed the attack on trained terrorists.
It is not clear if the attacks were to protest Pakistan's support for the U-S-led military campaign in Afghanistan.
In recent weeks, Quetta has been the site of violent demonstrations against Pakistan's support of the U-S bombing.
The U-S-led campaign is aimed at Osama bin Laden -- the chief suspect in the September 11th suicide hijackings in the United States -- and at Afghanistan's Taleban rulers, who have refused to hand him over.