Police beat demonstrators with batons. Later in the day, tens of thousands of protesters converged in a neighborhood and called for the maker of the film, an American citizen originally from Egypt, to be executed.
Police and stone-throwers also clashed in Lahore and Islamabad, the capital. Police fired tear gas and warning shots to try to keep them from advancing toward U.S. missions in the cities.
Hospital official Tanveer Malik says 25 people were wounded in Islamabad.
Police clashed with over 10,000 demonstrators in several neighborhoods, including in front of a five-star hotel near the diplomatic enclave where the U.S. Embassy and other foreign missions are located. A military helicopter buzzed overhead as the sound of tear gas being fired echoed across the city.
The government temporarily blocked cellphone service in 15 major cities to prevent militants from using phones to detonate bombs during the protests, said an Interior Ministry official, speaking on condition of anonymity because he was not authorized to talk to the media. Blocking cellphones could make it harder for people to organize protests as well.
Pakistan's Foreign Ministry on Friday summoned the U.S. charge d'affaires in Islamabad, Richard Hoagland, over the film. Pakistan has banned access to YouTube because the website refused to remove the video.