The Pakistan-born Bishop of Rochester, the Rt Rev Michael Nazir-Ali, has called the assassination of Benazir Bhutto a "body blow for freedom and democracy in Pakistan".

Bhutto, the former prime minister of Pakistan and leader of the opposition, was killed in a gun and suicide bomb attack on Thursday as she was leaving a political rally at Rawalpindi. Sixteen people were killed in the attack.

Bishop Nazir-Ali, who is the former Bishop of Raiwind Lahore and who was forced to flee Pakistan as a result of persecution, said Bhutto had been a "friend for many years".

"Her murder by extremists is a body blow for freedom and democracy in Pakistan," he was quoted by Times Online as saying.

"It raises serious questions about the government's ability to provide security for its citizens when even one as eminent as she can be killed in this way."

Pakistani officials have assured that the general elections on January 8 will go ahead as scheduled.

Bishop Nazir-Ali continued, "I do hope the general elections can still be held and that the cause of democracy can survive this catastrophe.

"My prayers are for her husband, children and family that they will be comforted at this time of grief. She will always be remembered for her commitment to Pakistan and her courage in public life."

Other Christians have also paid tribute to Bhutto for her lifelong commitment to building a democratic Pakistan.

Christine Elliot, the Methodist Church's World Church Secretary for Asia and the Pacific, said that it was a "very sad day... for the people of Pakistan", adding that the assassination of Bhutto was a "desperate blow" for the hope of a new democratic government in Pakistan.

She went on to express concern that the assassination could seriously the longshake stability in Pakistan in the long term.

Since Bhutto's death on Thursday, 40 people have killed in rioting and violent protests. Shops, lorries, welfare centres, ambulances and buses have all been torched in the chaos.

"The situation in the country over the next hours and days will be very precarious, particularly in the Sindh province," she warned.

"Our partners in Pakistan are concerned that civil war may erupt and that military rule will be re-imposed further - there is a desperate feeling that it will be really difficult to recover from this tragedy."

She urged Christians to pray for the country, saying, "We have been asked to pray with and for the people of Pakistan, for peace and stability, and hope that others will join us in this task."

The Executive Director of the World Evangelical Alliance's Religious Liberty Commission, the Rev Johan Candelin, worked with Bhutto, 54, extensively over the years to further democracy.

He called her murder "one of the most tragic events in the history of Pakistan".

"After working together with Mrs Bhutto for democracy for several years I can say that her importance for democracy and human rights in Pakistan can never be underestimated," he stated.

Having had a Catholic nun as a home teacher in Pakistan, Bhutto had great respect for the Christian faith and a strong desire to protect all religious minorities, according to Rev Candelin.

"She told me several times that she wanted to work for Pakistan where a Jew could go to the synagogue, a Christian to the church and a Muslim to the mosque - all without any fear," he said. "She was fully aware of the risk she took when she went back to Pakistan, but said that democracy is worth risking one's life for."

Benazir Bhutto's father, Zulfikar Ali Bhutto, became the country's first popularly elected prime minister. He was ousted in a military coup in 1977, however, and later hanged.

In 1988, aged just 35, Bhutto became the Muslim world's first democratically elected woman prime minister. Deposed in 1990, she was re-elected in 1993, and ousted again in 1996 amid charges of corruption she said were politically motivated.

She was laid to rest on Friday in the mausoleum she built for her father.