Outside the embassy, thousands of demonstrators gathered, including stone-throwing protesters who clashed with police, an Associated Press reporter on the scene said. Officers responded with tear gas and gunshots.
Protesters also set fire to an American school adjacent to the embassy compound, and firefighters were prevented from approaching by the large crowd. Thick columns of black smoke wafted through the neighborhood. The group that breached the embassy's outer wall was pushed back outside by police and special forces.
A Tunisian employee of the embassy with an injured leg was taken out by stretcher to an ambulance. It wasn't immediately clear if there were any other injuries.
Crowds angry over an anti-Muslim film ridiculing the Prophet Muhammad have assaulted U.S. embassies across the Middle East.