Fear of terrorist attacks on Friday prompted Britain and Germany to plan closings of diplomatic outposts in Yemen as London warned its citizens to leave the country, dpa reported.
The British and German embassies are to be shuttered on Sunday and Monday. The move came as the United States issued a worldwide travel alert over terrorist threats and moved to close down 21 diplomatic posts in 17 countries on Sunday and possibly the following days.
The US cautioned its citizens worldwide of the "continued potential" for al-Qaeda and groups allied with the terrorist network to mount attacks. The main threat emanated form the Arabian Peninsula, the US State Department said.
Germany's diplomatic outposts in Yemen were to remain closed on Sunday and Monday out of security concerns, a spokesman for the foreign ministry in Berlin told dpa late Friday. He did not give further details or background.
A spokeswoman in the British Foreign Office said its embassy in the Yemen capital of Sana'a would also be closed on the two days. The official said it was a "precautionary measure."
The British Foreign Office warned British nationals to leave Yemen immediately, amid fears of escalating violence in the country. It warned that Britons who stay in Yemen would unlikely get help in being evacuated if things got worse.
Clashes in Sana'a were reported Friday by Britain's Press Association, which said a group of soldiers had joined a mutiny that tried to storm the presidential palace. One of the mutineers was killed, and tanks and armoured vehicles were deployed to protect the palace.
On Thursday, three militants with suspected links to al-Qaeda were killed in a US drone strike in eastern Yemen, hours before the presidents of both countries were to meet in Washington. Earlier in the week, a drone strike killed four suspected al-Qaeda militants in Shabwa province, also in eastern Yemen.
At the White House meeting on Thursday, US President Barack Obama and Yemeni President Abdo Rabu Mansour Hadi agreed to work together to send Yemeni detainees home from the US prison at Guantanamo Bay.
Hadi told Obama he would establish an "extremist rehabilitation programme to address the problem of violent extremism within Yemen. Obama and Hadi pledged cooperation on counterterrorism measures against al-Qaeda in the Arabian Peninsula and Yemen's political transition.
The German Foreign Ministry in Berlin did not change its travel warnings for German citizens, saying security measures were always adapted to the current security situation. "We are in close contacts with our allies," the spokesman said.
Experts say that the escalating terrorist danger accompanies the end of the Muslim fasting month of Ramadan.
At the same time, August will start the buildup to the September 11 anniversary of the 2001 terrorist attacks on the United States. On September 11, 2012, terrorists attacked the US consulate in Benghazi, Libya, killing the US ambassador and three other US diplomats.