Pakistani Minister for Minorities Shahbaz Bhatti, who had called for changes in the country's controversial blasphemy law, has been killed in a gun attack in Islamabad.
Police said the shooting took place near an Islamabad market. Mr Bhatti was the only Christian in the Pakistani cabinet.
A hospital spokesman said Mr Bhatti had several bullet wounds.
The anti-blasphemy law has been in the spotlight since last November, when a court sentenced a Christian mother of four to death.
On 4 January, the governor of the most populous province of Punjab, Salman Taseer, who had strongly opposed the law and sought presidential pardon for the 45-year-old Christian farmhand, was gunned down by one of his bodyguards.
Liberal Pakistanis and rights groups believe the law to be dangerously discriminatory against the country's tiny minority groups.
Under the law, anyone who speaks ill of Islam and the Prophet Mohammad commits a crime and faces the death penalty, but activists say the vague terminology has led to its misuse.
Christians who make up about 2% of Pakistan's population have been especially concerned about the law saying it offers them no protection.
Blasphemy convictions are common, although the death sentence has never been carried out. Most convictions are thrown out on appeal, but angry mobs have killed many people accused of blasphemy.
'Bhahti a brave man'
Irish campaigners for the rights of persecuted Christians have condemned the Taliban's assassination of Pakistan's only Christian cabinet minister.
The 'Church in Chains' group described Mr Bhahti as a brave man who devoted his life to the cause of religious freedom in Pakistan.
In a statement, the group's director David Turner said Mr Bhati had been outspoken in calling for changes to his country's Blasphemy Law.
He said this, together with his support for Asia Bibi, had led directly to his killing.
Mr Bhatti recorded a video to be released in the event of his assassination. In it he reaffirmed his commitment to tackling religious discrimination despite threats to his life.
Earlier, the Vatican condemned the murder as 'an unspeakable act of violence'.
In a statement, it appealed for a heightened global awareness of the urgent need to defend both religious freedom and Christians who are subject to violence and persecution.
Mitchell condemns 'callous' murder
The MEP for Dublin, Gay Mitchell, has condemned what he called the ‘callous’ murder of Shahbaz Bhatti.
He said Mr Bhatti’s stand for freedom and had been brutally repaid and called for those responsible to be brought to justice.
Mr Mitchell said that apart from the sad loss that Mr Bhatti's family and country had to endure as a result of the murder, it was an even more tragic occurrence as Mr Bhatti campaigned endlessly in defence of religious freedom and against the persecution of Christian minorities in Pakistan.
He praised Mr Bhatti's determination to protect vulnerable minority groups in his country and said his stand for freedom and had been brutally repaid today.
Describing the killing as ‘a shocking escalation of an already gravely worrying situation developing worldwide,’ Mr Mitchell called on the peoples of the European Union to continue to uphold the values of religious freedom and to protect human rights around the world.
Mr Mitchell, who is a member of the European Parliament's Working Group on Religious Freedom and Intercultural Dialogue, said the tragic death of Mr Bhatti was frighteningly indicative of the growing danger that an intolerant society presents.
He added that people in Europe or around the world could not be allowed to fear for their lives because of their religious beliefs.
He called for those responsible for the murder of Mr Bhatti to be brought to justice.
