Britons in Yemen have been advised to leave immediately after the British embassy was closed, following a takeover of the country by Shiite rebels.
The Foreign and Commonwealth Office said today diplomatic staff were being withdrawn from the country's capital Sanaa amid security fears, saying they were at "increased risk". The US State Department also said it had closed its embassy and evacuated staff.
The United States has reduced the level of staffing at its embassy in Yemen, Reuters news agency reports citing a senior US official.
The change follows several days of clashes around the President's residence in Sanaa.
The army and Houthi fighters clashed in Yemen's capital Sanaa today near the Yemeni president's house, a Reuters witness said.
Gunfire was heard across the city and within close proximity to the president's residence. No further details were immediately available.
A top al Qaida leader in Yemen has blamed US President Barack Obama for the recent deaths of two hostages during a failed rescue attempt.
Nasr bin Ali al Ansi's video message, obtained by Site Intelligence, is the first comment by al Qaida following the deaths of Luke Somers, a British born American, and South African Pierre Korkie.
Al Ansi said he warned the US against such attempts after a first failed rescue operation in November.
He accused Obama of showing carelessness for the life of an American citizen and claimed the raid "caused things to go in a completely different way than we wanted".
The family of Luke Somers, the British-born US citizen killed by al Qaida militants in Yemen on Saturday, have told reporters they are angry about the US military's failed rescue attempt and said they were "kept in the dark" about the mission.
Somer's step-mother Penny Bearman told The Times(£) her husband was “quite angry . . . because if there had not been a rescue attempt he would still be alive.”
Bearman added that a military raid to save him is not what her step-son would have wanted.
She said: “We are sure that Luke would have given support to the ongoing discussions [to secure his release] in Yemen rather than the conflict approach."
The South African government said it was saddened by the death of hostage Pierre Korkie, who was killed during a failed US rescue mission in Yemen.
In a statement, the government expressed its "firm and unconditional condemnation of all forms of terrorism that invariably result in the senseless suffering and loss of innocent lives".
The South African government have confirmed that the body of slain hostage Pierre Korkie will be returned home tomorrow.
Korkie had been due to be released by al Qaida militants but died alongside fellow hostage Luke Somers during a failed US military rescue mission yesterday.
Reports have suggested that US forces, who launched a rescue mission to try and save photojournalist Luke Somers from al Qaida in Yemen, did not know the identity of the second hostage also being held by the rebel group.
A US official told the BBC that US special forces were unaware South African national Pierre Korkie was being held hostage when they launched their raid to free Somers yesterday.
Korkie had been due to be released by the end of the weekend but died alongside Somers after being shot by militants during the raid.
A statement on charity website Gift of the Givers, who had been arranging Korkie's release, confirms: "Pierre was to be released by al Qaida."
The US President Barack Obama and Foreign Secretary Philip Hammond have condemned the killing to two western hostages held in Yemen.
British-born American Luke Somers and South African Pierre Korkie died during a failed rescue mission, launched by the US a few days ago after it said there were "compelling reasons" the men's lives were in danger. Duncan Golestani reports.
Foreign Secretary Philip Hammond today offered his condolences to the families of Mr Somers and Mr Korkie.
Mr Hammond said: "My deepest condolences are with the families of both hostages at this time. We utterly condemn AQAP for the brutal murder of these two men."
He added: "I salute the forces involved, who showed great courage in carrying out this mission.
"We continue to work with our international and Yemeni partners to counter the threat from al Qaida and other terrorist groups."