Suspected al-Qaeda fighters have killed five Yemeni soldiers in their sleep in southern Yemen, according to local officials.
An official talking to Reuters news agency said that the soldiers were killed early on Sunday in an attack on forces guarding the country's only liquefied natural gas (LNG) export terminal in Balhaf.
"The attackers arrived in a car at the army checkpoint near the Balhaf terminal. They opened fire with automatic weapons, killing five soldiers before fleeing," a separate military source told AFP news agency, refering to "al-Qaeda elements" as the perpetrators of the attack.
The attack follows an escalating campaign of drone strikes by the US over the past two weeks after a worldwide travel warning that forced the US to close its embassy in Sanaa, Yemen's capital, and evacuate some staff.
A drone attack in Yemen's southern Lahij province destroyed a vehicle travelling on a mountain road and killed the two suspected al-Qaeda members inside it on Saturday, according to local officials and residents.
The attack was the fourth of its kind in the last three days that killed 15 people in total.
Yemen said on Wednesday that it had foiled a plot by al-Qaeda to seize the port of Mukalla, the capital of Hadramawt province and a major oil and natural gas export hub.
The US closed has closed some most of its embassies and consulates in the Middle East and North Africa since August 4 after reported intelligence intercepts from al-Qaeda suggested an attack is imminent.
The US administration has said it would reopen 18 embassies and consulates except for its Yemen mission, which will remain closed.
Yemen is one of a handful of countries where Washington acknowledges using drones, but it does not publicly comment on drone attacks.