Raja Pervez Ashraf, Pakistan's prime minister, has ordered YouTube to be blocked after the site "refused to heed to the advice of the government of Pakistan to remove blasphemous film from its site", a statement from his office said.
Attempts to access YouTube on Monday met with a message saying the website had been classed as containing "indecent material" and was blocked on the orders of the Pakistan Telecom Authority.
Authorities in Bangladesh have also blocked the video-sharing site indefinitely to prevent citizens from watching the video that mocks the Prophet and Islam.
Protests against the anti-Islam video continued on Monday, several of them violent, in various countries across the Muslim world.
Protests were also reported from Indonesia, Afghanistan, the Philippines, Yemen and Lebanon.
In Kabul and Jakarta, protests turned violent for the first time since the furore over the film mocking Islam first broke out last week. Hundreds of angry men clashed with police, hurled stones and shouted "Death to America".
Thousands of followers of Lebanon's powerful Hezbollah group rallied against the anti-Islam film that has provoked a week of unrest in Muslim countries worldwide, as Hassan Nasrallah delivered his first major public address in four years.
Most of the men tied headbands around their foreheads in green and yellow - the colours of Hezbollah - with the words "at your service God's prophet" written on them.
Meanwhile, more than 1,000 Tunisian security forces briefly surrounded a mosque in the capital on Monday where a Salafi leader wanted by police over clashes at the US embassy last week was meeting hundreds of followers.
The Reuters news agency reported that Saif-Allah Ben Hassine managed to escape the mosque, however.
And Libya's interior minister has sacked Benghazi security chiefs after last week's deadly attack on the US consulate in
the eastern city.
the eastern city.
Police in Azerbaijan detained about 30 Muslim activists on Monday while preventing a protest from breaking out near the US embassy.