Widespread protests over Islam film
The protests over the obscure movie about Mohammad have escalated around the world.
Three protestors died after thousands of people attacked the US embassy in Khartoum, according to Sudanese state radio.
The mob initially attacked the German embassy and set fire to it, causing severe damage.
The British embassy nearby also saw protests but was not damaged. Germany and the UK have no link to the film.
"I condemn in the strongest possible terms today's attack and call on the Sudanese authorities to ensure that those involved are brought to justice," said UK Foreign Secretary William Hague.