The World Council of Churches (WCC) said on Monday it was concerned Pakistan's leaders were not taking steps to prevent attacks against the country's Christian minority, following three recent violent incidents that have caused deaths and damage to property.
Seven Christians were "burned alive" on Saturday, the Geneva-based organisation said, and 40 houses belonging to members of churches were torched in Gojra, a city in the eastern province of Punjab.
"The killings and destruction of houses could have been avoided if the police and security forces were vigilant and had taken timely action against the militant Islamic groups," wrote Samuel Kobia, the head of the WCC, to Pakistan President Asif Ali Zardari.
Kobia said the Islamist groups "constantly threaten the Christian minorities with false allegations of desecrating the Koran".
The riots Saturday erupted when participants of a rally to protest the alleged desecration of the Muslim holy book started hurling stones at the Christian houses, triggering a brief exchange of fire between the two groups.
Federal Minister for Minorities Shahbaz Bhatti said following the incidents that the police and civilian administration did little to protect Christians.
Tension had been growing between the two communities since 75 houses of Christians were set ablaze in a nearby village two days earlier on the same blasphemy charges.
Kioba called Saturday's incidents "carnage" and said Zardari should prosecute those responsible and "ensure the safety and security" of minorities in the country.
Christians constitute between two and three percent of Pakistan's 160 million citizens.