The Los Angeles Times reports: Hundreds of Yemeni protesters stormed the U.S. Embassy in Sana and started fires on Thursday, another eruption of violence in a series of protests sweeping the Middle East and elsewhere over an online trailer for a film mocking the Islamic prophet.

Four protesters were killed and more than 30 were injured, some of them severely, after security forces fired gunshots and lobbed tear gas into the air in an attempt to scatter the demonstrators, a Yemeni security source said on condition of anonymity.

Infuriated protesters smashed security office windows and broke past barriers, hurling stones at buildings and setting two cars on fire outside. Demonstrators tore down the American flag and lifted a white banner saying, “There is no god but Allah and his messenger is Muhammad.” Graffiti sprayed on the walls read, “For the prophet.”

“I went to this demonstration to defend my religion and to denounce this crime, which we consider a great violation against the divinity of Islam and its symbols,” said protester Mohamed Ahmed.

Others demanded that the embassy be shuttered. “It is not the first time they insulted the Koran and Islam, and I think it is about time to close the U.S. Embassy and kick out its ambassador,” another demonstrator told The Times.

Witnesses said Yemeni security forces guarding the embassy had stepped aside at first, allowing protesters to breach the grounds before opening fire. Reaching the embassy gate, which is normally heavily guarded, typically requires passing both two armed vehicles and a checkpoint, making it difficult to pass. Protesters didn’t enter the main offices of the embassy.