The Yemeni army foiled a car bomb attack on the Anad air base used by US soldiers in the southern province of Lahj, a military official told AFP on Saturday.
"We foiled an attack by a car packed with explosives that managed to breach several security checkpoints leading into the air base," said the official who spoke on condition of anonymity.
He said the "Americans on the base were the target of the attack."
According to the official, some "15 American soldiers have been on the base for two months training Yemeni forces in combating terrorism."
The car was "disarmed" and an investigation launched, he said, without reporting any arrest though the army "suspects Al-Qaeda" was likely to be responsible.
Taking advantage of the weakening of central government control by an Arab Spring-inspired uprising last year, Al-Qaeda overran most of southern Yemen's Abyan province, seizing its capital Zinjibar and several other towns.
On May 12, under orders from President Abdrabuh Mansur Hadi, the army launched a massive offensive to recapture territory lost to the militants.
Western diplomats at the time said US experts were assisting the army in their battle to destroy Al-Qaeda in the Arabian Peninsula, the network's local branch, considered by Washington to be the deadliest and most active.
The US also continues to target militants using unmanned drones against AQAP.
Washington has never formally acknowledged the presence of troops on the ground in Yemen to assist in the offensive against Al-Qaeda.