The British Ambassador to Yemen escaped unharmed after an explosion near his car today, the Foreign Office confirmed.
The blast happened as Tim Torlot, 52, travelled to work in the Yemeni capital of Sana'a.
The Foreign Office was unable to confirm reports that a suspected suicide bomber died in the explosion.
A Foreign Office spokesman said: "We can confirm that there was an incident in Sana'a this morning.
"There was a small explosion beside the British Ambassador's car. He was unhurt. No other embassy staff or British nationals were injured.
"The embassy will remain closed to the public for the time being.
"We advise all British nationals in Yemen to keep a low profile and remain vigilant. We are working urgently with the Yemen authorities to investigate what happened."
The blast comes after Yemen became a focus of international concern about al Qaida activity after the man suspected of attempting to blow up a US-bound airliner on Christmas Day, Umar Farouk Abdulmutallab, was reported to have told FBI investigators that he was supplied with his bomb by al Qaida members in Yemen.
Nigerian-born Abdulmutallab's family have also suggested that he became radicalised during a visit to Yemen last year, where he was supposedly studying Arabic but is believed to have made contact with some of the estimated 300 al Qaida militants based in the country.
The British Embassy in Yemen closed for two days in January for security reasons, one of a number of Western embassies - including the US and France - which shut their doors in the country amid concerns over a possible threat from al Qaida militants.
Yemen's government has recently vowed to work with the US in taking on the al Qaida fighters who have built up strongholds in the country's remote regions.
The Foreign Office website warns travellers that there is a "high threat" of terrorism in Yemen.
"We believe that terrorists continue to plan attacks," it said.
"Attacks could be indiscriminate, including against Western and British interests, such as residential compounds, military and oil facilities, and transport and aviation interests."
Mr Torlot took up his posting as UK Ambassador to Yemen in 2007. His previous postings have included deputy head of mission at the British Embassy in Baghdad, Iraq.
His private life has been the subject of press coverage after he reportedly moved his pregnant mistress, US journalist Jennifer Steil, into his official residence after his wife of 23 years returned home.
The couple now have a baby daughter.
Yemeni sources said Mr Torlot's armoured car had been travelling through a neighbourhood in the eastern part of Sana'a known to be popular with militants when the explosion happened.
It is believed the attacker, a young man apparently dressed in school uniform to disguise himself, was wearing an explosives belt and that he was killed in the blast.
Security has been stepped up around the US and British Embassies following the attack.Reuse content