Pakistani authorities have ordered ISPs to block access to Facebook ahead of an "Everybody Draw Mohammed Day" planned by users for tomorrow.
Prompted by a court order, the Pakistan Telecommunications Authority today told providers to suspend access. The order runs until 31 May.
The Facebook group for "Everybody Draw Mohammed Day" has more than 43,000 supporters.
The group has become a target for protest in Pakistan, and today a group of Islamic lawyers obtained a court order for a full suspension of Facebook. The government had previously blocked access to only the "Everybody Draw Mohammed Day" pages.
The group's organisers say it is not designed to offend ordinary Muslims, but as a demonstration of their right to free speech and "to show the extremists... that we're not afraid of them".
Islamic teaching typically forbids depictions of its prophet. After online threats of violence last month, the US cable network Comedy Central bleeped Mohammed's name in an episode of South Park that featured him hidden in a bear suit.
The episode itself sought to satirise the wave of Islamic outrage that greeted a Danish cartoonist's depictions of Mohammed in 2005. In the same episode Jesus was shown watching porn and Buddha snorting cocaine. ®