Pakistani police fired in the air to disperse a crowd headed towards the U.S. consulate in the city of Karachi to protest against a film mocking the Prophet Mohammad.
A senior police official said 30 students were arrested at the demonstration organized by a religious party.
Demonstrations have spread in the Muslim world over the amateurish video, posted on the Internet under several titles including "Innocence of Muslims".
Protests erupted in several Pakistani cities over the weekend.
In Monday's demonstration, protesters on motorcycles and in cars headed towards the U.S. consulate in Pakistan's commercial hub, prompting police to open fire in the air and use teargas.
Protesters threw rocks at the police and damaged one of their vehicles. Around 100 people were scattered in roads and alleys near the sprawling U.S. compound.