Islamic fanatics have murdered the only Christian in Pakistan's cabinet for opposing the country's savage blasphemy laws.
Minister of Minority Affairs Shahbaz Bhatti, a Catholic in his 40s, was sprayed with bullets outside his parents' home in Islamabad.
The killing today further undermines Pakistan's shaky image as a moderate Islamic state and could deepen the political turmoil.
In pamphlets found at the scene of the shooting, al Qaida and the Pakistani Taliban said they targeted Mr Bhatti because of his faith and because he allegedly belonged to a committee that was reviewing the blasphemy laws which at the moment carry the death penalty for insulting Islam.
Mr Bhatti had just pulled out of the drive when three men standing nearby opened fire.
Two of the men opened the door and tried to pull him out, as a third fired his Kalashnikov repeatedly into the car. The killers then drove off.
The government condemned the killing but made no direct reference to the blasphemy law controversy that apparently motivated the assassins.
"This is concerted campaign to slaughter every liberal, progressive and humanist voice in Pakistan," said Farahnaz Ispahani, an aide to President Asif Ali Zardari.
"The time has come for the federal government and provincial governments to speak out and to take a strong stand against these murderers to save the very essence of Pakistan."
In January, Punjab province governor Salman Taseer was killed by a bodyguard angry that the politician opposed the blasphemy laws. To the horror of Pakistan's besieged liberals, many ordinary citizens praised the assassin - a sign of the spread of hardline Islamic thought in the country.
After the killing of the Punjab governor, Mr Bhatti also received death threats.
The leaflets at the scene of the shooting blamed the government for putting Mr Bhatti, an "infidel Christian," in charge of an unspecified committee and said that "this is the horrible fate of this cursed one."
"With the blessing of Allah, the mujahedeen will send each of you to hell," said the note, which did not name any other targets. The committee it was apparently referring to was one said to be reviewing the blasphemy laws, though the government has repeatedly said no such committee existed.
Pakistani Christians reeled from the loss of their most prominent advocate. Christians are the largest religious minority in the country, where roughly 5% of 180 million people are not Muslim. They have very little political power and tend to work in lower-level jobs, such as street sweeping.
The blasphemy laws are a deeply sensitive subject in Pakistan, where most are Sunni Muslims and where austere versions of Islam - more common in the Middle East than South Asia - have been on the rise.
Human rights groups have long warned that the laws are vaguely worded and open to abuse because people often use them to settle rivalries or persecute religious minorities.
But in a sign of how scared the largely secular-leaning ruling party is of Islamist street power, party leaders have not supported calls for reforming the laws. Instead, Prime Minister Yousuf Raza Gilani and others have repeatedly insisted they will not touch the statutes.
After the assassination of the Punjab governor, his confessed killer, bodyguard Mumtaz Qadri, was greeted with showers of rose petals from many lawyers who went to watch his initial court hearing.
Weeks afterward, another prominent opponent of the blasphemy laws, National Assembly member Sherry Rehman, dropped her bid to get them changed. The People's Party member said she had to abide by party leaders' decisions. She, too, faces death threats and has been living with heavy security.
No one has been put to death for blasphemy in Pakistan because courts typically throw out cases or commute the sentences.
However some who are released are later killed by extremists or have to go into hiding. Others spend long periods in prison while waiting for their cases to wind through the courts.
The laws came under renewed international scrutiny late last year when a 45-year-old Christian woman, Asia Bibi, was sentenced to death for allegedly insulting the Prophet Mohammed.
The family of Mrs Bibi - a mother of five - insists she was falsely accused over a personal dispute. There have been appeals from around the globe, including one from the Pope, to pardon her. But the government has said it is first waiting for a court ruling on her appeal.