A Florida pastor's plan to burn copies of the Qur'an led to large protests across Afghanistan on Friday.
The protesters burned U.S. flags and chanted "Death to Christians."
At least 11 people were reported injured across the country during the demonstrations.
Police said four demonstrators and five police officers were injured in clashes in the northern province of Badakhshan after protesters attacked a NATO base.
Police denied earlier reports that one person was shot and killed outside the base.
Meanwhile, police in the western province of Farah said two people were injured in another protest at a mosque.