ABYAN PROVINCE, Yemen (CNN) -- Yemeni Air Force fighter jets killed 17 militants in an airstrike on an al Qaeda hideout in Mahfed, Abyan province on Wednesday, Yemeni security officials told CNN.
Weapons caches left behind by the militants were found after the raid, the officials said. Six others were injured in the attack, they said.
Yemen's defense ministry confirmed airstrikes in the valley of Thaiqa, Mahfed district, calling them successful. The minister would would not officially estimate casualty numbers.
Government troops have gained ground against al Qaeda since President Abdurabu Hadi came to power as part of a Gulf-brokered power transfer in February.
Most towns previously under al Qaeda control were retaken by government forces this month.
Al Qaeda retaliated Tuesday by killing Salem Qatan, the top military commander in Yemen's southern region. He led the offensive against al Qaeda in Abyan.
An aid worker died in an airstrike in Abyan Wednesday morning, the International Committee of the Red Cross said.
The worker who was killed , identified as Hussein Saleh, and three other Red Cross workers were assessing the humanitarian situation in areas severely affected by the recent fighting, the Red Cross said.
"We are devastated by the tragic loss of our friend and colleague Hussein," said Eric Marclay, the head of the ICRC delegation in Yemen. "He was a very motivated and devoted staff member. He played a tremendously crucial role within his team helping hundreds of thousands of people in the south, and lost his life while performing humanitarian work."