Facebook has blocked the popular page of a liberal Pakistani rock band and others that criticise the Taliban at the request of the government, angering activists campaigning against censorship in the Islamic country.
Rock band "Laal" (Red) formed in 2007 and are known for their progressive politics.
Their Facebook page has more than 400,000 likes, with users frequently joining debates on issues ranging from feminism to the role of the country's army in politics.
But it has been inaccessible to users from inside Pakistan since Wednesday.
Other pages like "Taalibansarezalimans" (The Taliban are oppressors) and "Pakistani.meem" which describes itself as pro-democracy and secularism, have similarly been blocked in recent days.
"Facebook didn't even inform us, I realised when I noticed no activity on our page," Taimur Rahman, Laal's lead guitarist, told AFP.
Facebook confirmed the move to AFP Friday saying Laal's page had been blocked inside Pakistan at Islamabad's request, under an agreement to limit access to material that violates local laws.
A Facebook spokeswoman said: "While we never remove this type of content from the site entirely, like most Internet services, we may restrict people from accessing it in the countries where it is determined to be illegal.
"Before we restrict the content, we take significant steps to investigate each unique claim, consult with local counsel and other experts in the country, and will only remove content in the most limited way possible," she added.
According to a page on Facebook that deals with government requests, 162 pieces of content were restricted for viewership inside Pakistan between July to December 2013.
"We restricted access in Pakistan to a number of pieces of content primarily reported by the Pakistan Telecommunication Authority and the Ministry of Information Technology under local laws prohibiting blasphemy and criticism of the state," the page says.
Pakistan practises extensive Internet censorship, blocking YouTube in 2012 following the release of a low-budget film that was critical of Islam. Websites for Baluch separatist movements in the country's southwest are also banned.
While attempts to access those sites result in a government message informing the user that the content has been blocked for viewership within Pakistan, clicking Laal's page (www.facebook.com/laalpak) or the other liberal pages instead re-directs a user towards their own home feed.
Shahzad Ahmad, director of the Bytes For All organisation that campaigns for free speech said: "The is a mass murder of free speech in Pakistan."
Yasser Latif Hamdani, a lawyer, added: "This is a grave mistake by Facebook. Also for the Pakistani government to make such requests is illegal and unconstitutional."
Pakistan's agreement with Facebook came to light last year when a senior official from the Pakistan Telecommunication Authority, an Internet regulatory body, was summoned by the Lahore High Court in a case concerning the YouTube ban, but its terms have not been made public.
'Pack of lies'
When called for comment on Friday, Khurram Ali Mehran, a spokesman for the regulatory body denied the existence of such an agreement, saying Facebook had acted alone. "We have no agreement with Facebook whatsoever, it's a pack of lies," he said.
"We have not closed the page of Laal, Facebook has its own terms of reference and it closes pages that seem indecent to them," he added.
Rahman, the musician, said the blocking of the page was indicative of diminishing space for liberals in the country.
"If you have progressive or liberal views you will be gunned down or silenced but if you have extremist views and take up arms Pakistan will give you the status of a stakeholder in power and negotiate with you," he said.
Explore further: Former federal agent pleads guilty to stealing bitcoins