Protesters on Tuesday ransacked offices of a Pakistani daily shut down for printing an allegedly blasphemous letter, but the national journalists' union demanded an immediate revival of the independent newspaper.
The Frontier Post, the only English-language daily in the North West Frontier Province, was summarily shut by authorities on Monday and six of its staff were detained after publication of the controversial letter about Islam's Prophet Mohammad.
A senior police official in the provincial capital Peshawar said a few hundred members of the right-wing Jamaat-e-Islami party ransacked offices of the Post and burnt its printing press, housed in a nearby building.
The extent of the damage was not immediately known but the fire was put out quickly.
Several hundred students from nearby Peshawar University also marched through the city in protest against the newspaper but witnesses said they dispersed peacefully later.
The objectionable letter, which journalists said was apparently picked up from the Internet, also brought a statement of condemnation from military ruler General Pervez Musharraf.
Musharraf, quoted by the official APP news agency, said the letter had hurt sentiments of all Muslims and "the government will not allow publication of such objectionable material".
He said firm action had already been taken and "offenders will be proceeded against strictly in accordance with the law".
But Abdul Hamid Chhapra, chairman of All-Pakistan Confederation of Newspaper Employees Confederation, said: "The government cannot be both the prosecutor and the judge."
He told a meeting of newspaper employees in Islamabad, the national capital, that the government should immediately allow the Post to resume publication and prosecute only those responsible for inserting the objectionable letter.
Chhapra said the Post had been an independent newspaper since it started 15 years ago and should not be closed down for any individual's act.
The Post carried large advertisements in several national dailies on Tuesday apologising for the letter, which criticised Mohammad's dealing's with Jews nearly 14 centuries ago.
On Monday the Post's chief editor, Mahmood Afridi, said he suspected two disgruntled staff members may have inserted the letter in the newspaper to harm it.
Afridi, who was not in Peshawar at the time, was listed as an accused in a complaint under the country's blasphemy laws, which prescribe the death penalty for blasphemy against Mohammad.
"We once again beg pardon from the Muslim Ummah (nation) from the depths of our heart," the advertisements read.