The Pakistani government has blocked the popular social networking website Facebook because of a page inviting users to submit pictures of the Prophet Muhammad.

The page, titled "Everybody Draw Mohammed Day!", was created in April to protest threats made by a Muslim group against the creators of the cartoon television show South Park after they depicted Muhammad in a bear suit during an episode earlier this year.

But it has sparked outrage in Pakistan, where many Muslims consider images of the prophet, even favourable ones, to be blasphemous.

On Wednesday, the Lahore High Court ordered government officials to block the site until May 31, according to the deputy attorney general of Punjab province, Naveed Inayat Malik.

The Pakistani government on Tuesday ordered internet service providers in the country to block the page only, said Khurram Ali, a spokesman for the Pakistan Telecommunications Authority, which regulates the telecommunications network in the country.

Lawyers with the Islamic Lawyers Forum appealed to the higher court on Wednesday, saying the entire site should be blocked because it had allowed the page to be posted in the first place, Malik said.

Later in the day, the Pakistan Telecommunications Authority ordered all internet service providers to block Facebook, it said in a media release.

By Wednesday evening, access to the site was sporadic, apparently because internet providers were implementing the order.

'We're not afraid': creators

Lawyers outside the courtroom hailed the ruling, chanting "down with Facebook."

In the southern city of Karachi, 2,000 female students rallied demanding that Facebook be banned for tolerating the controversial web page. Several dozen male students held a rally nearby, with some holding signs that urged Islamic holy war against those who blaspheme the prophet.

Page creators insist they are "not trying to slander the average Muslim," according to the information section of the page.

"We simply want to show the extremists that threaten to harm people because of their Mohammed depictions that we're not afraid of them," they wrote. "That they can't take away our right to freedom of speech by trying to scare us into silence."

The page has drawn more than 44,000 supporters and prompted hundreds of comments including many that vow revenge for the page's creation.

It was based on a cartoon drawn by Seattle cartoonist Molly Norris shortly after Comedy Central, which airs South Park, censored the bear suit episode.

The cartoon depicted the prophet as a thimble, domino and teacup, among other things, and was dedicated to the show's creators, Matt Stone and Trey Parker.

It also invited people "to defend a little something [the U.S.] is famous for:" free speech.

A series of cartoons of the prophet published in a Danish newspaper in 2005 sparked violent protests and death threats against the cartoonists.