Officials in Yemen say suspected al-Qaida militants have attacked a natural gas terminal, killing five soldiers.
Authorities say the gunmen penetrated a security checkpoint Sunday before killing the soldiers at the Balhaf terminal in Shabwa province.
The attack comes after a series of U.S. drone strikes in the past two weeks that have killed militants in Yemen.
Washington closed its embassy in Yemen and 18 other embassies and consulates in the Middle East and African last week, following a worldwide alert that al-Qaida could be planning attacks.
All the missions, except the embassy in Yemen, were set to reopen Sunday.
The U.S. decided not to reopen the embassy in Sana'a, Yemen's capital, because of ongoing concerns about potential attacks that could be launched by al-Qaida in the Arabian Peninsula, the Yemen branch of the terrorist group.
On Saturday, Yemen's defense minister, Nasser Ahmed, discussed security issues with the U.S. deputy ambassador to Yemen, Karen Hideko Sasahara.
Yemen's state-run SABA news agency says Sasahara stressed the need to support Yemen's defense efforts, particularly in the area of counterterrorism.
The decision to keep the U.S. embassy in Sana’a closed came after U.S. intelligence intercepted electronic conversations in which the al-Qaida chief in Pakistan, Ayman al-Zawahri, ordered the head of its branch in Yemen to carry out an attack.
The intercepted intelligence did not specify where or when the attacks would take place.