The deadliest violence occurred in the southern port city of Karachi, where 12 people were killed and 82 wounded, according to Seemi Jamali and Aftab Channar, officials at two hospitals.
Armed demonstrators among a crowd of 15,000 in that city fired on police, according to police officer Ahmad Hassan. The crowd also burned two cinemas and a bank, he said.
Five people were killed and 60 wounded in the northwestern city of Peshawar, said police official Bashir Khan. Police fired on rioters who set fire to three movie theaters and the city's chamber of commerce, and damaged shops and vehicles.
One of the dead was identified as Mohammad Amir, a driver for a Pakistani TV station who was killed when police bullets hit his vehicle, which was parked near one of the cinemas, said Kashif Mahmood, a reporter for ARY TV who also was in the car. The TV channel showed doctors at a hospital trying unsuccessfully to save Amir's life.
Police beat demonstrators with batons and launched volleys of tear gas. 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.
Hospital official Mohammad Naeem says 45 people were wounded in Islamabad, including 28 protesters and 17 police.
Police clashed with over 10,000 demonstrators in several neighborhoods in the capital, 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.