The Government has raised "serious concerns" with the Sudanese Ambassador to Britain after the British Embassy in Khartoum was attacked by protesters.
Amid a wave of anger over an anti-Islam film, a compound containing both the British and German diplomatic missions was targeted, with demonstrators breaking down a perimeter wall.
Foreign Secretary William Hague said no staff were injured but urged the Sudanese government to bring those responsible to justice. "We have spoken to the Sudanese Ambassador in London (Abdullahi Hamad Ali Alazreg) and raised our serious concerns that this attack was able to take place," he said in a statement.
"It is the responsibility of the Sudanese authorities to ensure that effective protection is provided to diplomatic premises at all times. 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."
Mr Hague said the Foreign Office's travel advice had been updated to urge British nationals to avoid demonstrations or large gatherings of people.
The trouble comes with violence sweeping much of the Muslim world over a low-budget film produced in America that ridicules the Prophet Mohammed. Earlier this week the US ambassador to Libya, Chris Stevens, was killed in an attack in Benghazi. Protests have also taken place in Cairo and Yemen, while in Lebanon one person died when a KFC fast-food restaurant was burnt down.
Mr Hague said: "Earlier this afternoon the compound housing the German and British Embassies in Khartoum was attacked by a group of demonstrators. Sudanese police attended the scene, but demonstrators were able to break down a perimeter wall and cause minor damage to the compound. They did not attempt to gain access to the British Embassy building.
"As it is the Sudanese weekend, very few staff were present in the Embassy. I am glad to say that all UK and Sudanese staff present during the attack are safe and that no injuries were sustained. All other UK staff in Khartoum are also accounted for."
Mr Hague said the German Embassy appeared to have been the focus of the attack and had been set on fire and "severely damaged". The UK had offered shelter to German diplomats, who were also all safe.
Protests developed after Friday prayers in mosques after many clerics denounced the controversial film. The movie, called Innocence Of Muslims, portrays the prophet Mohammed as a fraud, a womaniser and a child molester. In an apparent attempt to improve strained relations with the US and contain the protests, Egypt's Islamist president Mohammed Morsi has urged Muslims to protect diplomatic missions. The US embassy in Tunis also came under attack today, with stone-throwing protesters and police waging a pitched battle.