Pakistan is being swept toward violent chaos by a growing wave of Islamist extremism, newspapers said on Thursday, a day after Taliban militants killed the country's only Christian government minister.

The assassination of minister for minorities Shahbaz Bhatti in broad daylight in the capital Islamabad on Wednesday, threatens to further destabilize the nuclear-armed U.S. ally where secular-minded politicians are imperiled by a rising strain of violent religious conservatism in the society.

"Mr. Bhatti's brutal assassination has once again highlighted the fact that we are fast turning into a violent society," the liberal Daily Times said in its editorial.

"This is not the time to be frightened into silence. It is time to implement the law and not surrender in front of extremists."

Bhatti is the second senior official to be assassinated this year for challenging the country's controversial blasphemy law, which sanctions the death penalty for insulting Islam or its Prophet Mohammad. Punjab provincial governor Salman Taseer was shot dead by his own bodyguard in January for calling for curbing abuses in the law.

"Terrorists silence another voice of interfaith harmony," the daily Dawn ran a banner headline on its front page. "Shahbaz Bhatti silenced forever," said The News.

President Asif Ali Zardari told a party meeting on Wednesday he would resist the slide toward extremism.

"We have to fight this mindset and defeat them. We will not be intimidated nor will we retreat the official APP news agency quoted him as saying.

Mehbood Ahmed, a senior police official, said around 20 people had been detained for questioning, but police did not yet know who was responsible. "But we are confident we will get hold of culprits," he said.

Condemnation poured in from around the world after news of Bhatti's killing broke, with the Church of England and the Vatican decrying the violence against Christians in Pakistan.

"I hope the government of Pakistan will not only hold the killers to account, but reflect on how it can more effectively confront the extremism which is poisoning Pakistani society," United Nations human rights chief Navi Pillay said from Geneva on Wednesday.

These killings, along with frequent militant attacks and chronic economic problems have raised fears for the future of the U.S.-ally, where an unpopular coalition government is struggling to cope.

'THERE'S BLOOD ON THEIR HANDS'

Ties between the two old allies have hit new lows after the arrest in January of Raymond Davis, a U.S. Central Intelligence Agency contractor, who shot dead two armed men in the city of Lahore. The United States says Davis has immunity, but Pakistan has said it is for the courts to decide.

In the meantime, Davis was in court on Thursday for the second hearing of his murder trial. His immunity hearing is March 14.

The government of President Asif Ali Zardari has repeatedly said it would not change the blasphemy law, and officials have distanced themselves from anyone calling for amendments for fear of a backlash from extremists, a move that dismayed moderates and liberals.

"Of course the silent majority, which keeps silent over these things, also must bear responsibility," I.A. Rehman, director of the Human Rights Commission of Pakistan, told the Express 24/7 television channel Wednesday night. "There's blood on their hands also."

The law has been in the spotlight since last November, when a court sentenced a Christian mother of four to death after her neighbors complained she had insulted Prophet Muhammad. Both Taseer and Bhatti championed the cause of poor Christian woman.

Al Qaeda-linked Pakistani Taliban militants, fighting to bring down the state, had called for Bhatti's death because of his attempts to amend the law.

The funeral of Bhatti, a Catholic, is expected to take place on Friday or Saturday, his family friends said.

Christians and other religious minorities have staged protests in several cities, denouncing his death and have called on the government to provide them protection.