Protesters angered by a film mocking Islam have attacked the German and British embassies in the Sudanese capital, Khartoum.
Demonstrators started fires and tore down the German flag, raising an Islamist banner in its place.
Protests are taking place across the Middle East and North Africa.
In Cairo, police firing tear gas pushed about 500 protesters back from the US embassy. There were also clashes in the Yemeni capital Sanaa.
A spokesperson for the UK Foreign Office has confirmed to the BBC that a demonstration is taking place outside the embassy in Khartoum, and said Sudanese police were at the scene.
However, the spokesperson could not confirm whether protesters had entered the embassy, or whether the demonstration was about the anti-Islam film.
Egypt's Islamist President Mohammed Mursi has called for protests to remain peaceful.
The streets around the US embassy in Cairo have been blocked with barbed wire, concrete and police vehicles.
Islamist groups and others had called for a peaceful "million-man march" in the city, but a number withdrew those calls on Friday.