Pakistan has blocked the popular video sharing website YouTube because of its "growing sacrilegious content".

Access to the social network Facebook has also been barred as part of a crackdown on websites seen to be hosting un-Islamic content.

On Wednesday a Pakistani court ordered Facebook to be blocked because of a page inviting people to draw images of the Prophet Muhammad.

Some Wikipedia pages are also now being restricted, latest reports say.

Correspondents say it remains to be seen how successful the new bans will be in Pakistan and whether citizens find a way round them.

Because YouTube is a platform for free expression of all sorts, we take great care when we enforce our policies.

 

YouTube says it is "looking into the matter and working to ensure that the service is restored as soon as possible". The site was briefly blocked in Pakistan in 2008 - ostensibly for carrying material deemed offensive to Muslims.

Facebook said on Wednesday that the content did not violate its terms.

There have been protests in several Pakistani cities against the Facebook competition.

'Derogatory material'

The Pakistan Telecommunications Authority said it had ordered internet service providers to "completely shut down" YouTube and prevent Facebook from being viewed within Pakistan.

It said the move came only after "all possible avenues" within its jurisdiction had been used.

Analysis

Continue reading the main story Zoe Kleinman Zoe Kleinman Technology reporter, BBC News

Countries, companies and even individuals can easily block various websites if they choose. China has a notorious firewall in place to control internet activity and many Western organisations choose to block access to social networks in the office.

In this case, Pakistan will probably have instructed its internet service providers (ISPs) to prevent any pages containing the phrase "youtube.com" in the address from loading on web browsers.

There are various ways of implementing a block and sometimes it can go awry - Pakistan accidentally pulled YouTube offline around the world in 2008 when it tried to implement an internal ban by "hijacking" the youtube.com address in order to re-direct links to a different page.

There are also ways to duck underneath a ban - most commonly by accessing the internet via a "proxy" server based abroad. This can fool an ISP into thinking a computer is actually based in another country and therefore not subject to the ban.

"Before shutting down (YouTube), we did try just to block particular URLs or links, and access to 450 links on the internet were stopped," said PTA spokesman Khurram Ali Mehran.

"But the blasphemous content kept appearing so we ordered a total shut down."

One of the links blocked is to a BBC News website article about Pakistani soldiers apparently beating Taliban suspects in a video posted on Facebook.

A YouTube spokesperson said: "YouTube offers citizens the world over a vital window on cultures and societies and we believe people should not be denied access to information via video.

"Because YouTube is a platform for free expression of all sorts, we take great care when we enforce our policies. Content that violates our guidelines is removed as soon as we become aware of it."

The controversy began with the Facebook feature called "Everybody Draw Muhammad Day". Depictions of the Prophet are forbidden in Islam.

A message on the item's information page said it was not "trying to slander the average Muslim".

"We simply want to show the extremists that threaten to harm people because of their Muhammad depictions that we're not afraid of them."

The page contains drawings and caricatures of the Prophet Muhammad and characters from other religions, including Hinduism and Christianity.

"Such malicious and insulting attacks hurt the sentiments of Muslims around the world and cannot be accepted under the garb of freedom of expression," Pakistani foreign ministry spokesman Abdul Basit said about the page.

Facebook said in a statement that it would take action if any content "becomes an attack on anyone, including Muslim people", but that in this case its policies were not violated.

"Facebook values free speech and enables people to express their feelings about a multitude of topics, even some that others may find distasteful or ignorant," the statement said.

A hotline has been set up in Pakistan, asking members of the public to phone in if they see offensive material anywhere.

Islamic parties say they are planning nationwide protests in Pakistan