Al Qaeda’s Yemeni wing has claimed responsibility for the assassination this week of a military commander credited with driving back allies of Al-Qaeda who had seized large parts of southern Yemen.

The killing of Major General Salem Ali Qatan in a suicide bombing in Aden was a reminder that government control of the south remains tenuous, despite a month-long US-backed assault that has driven militants out of all the towns they held.

In a statement posted on Islamist Internet forums on Thursday, Al-Qaeda in the Arabian Peninsula (AQAP) said the attack was a message to the “leaders of the joint American-Yemeni campaign.”

“The message ... consists of the blood and body parts of the martyrdom-seekers who swore to pluck your rotten heads, which agreed to be a vehicle for America in its war against the Muslims in Yemen,” the group said. It did not identify the bomber.

The Defense Ministry said on Monday that a suicide bomber had hurled himself at Qatan’s vehicle as he headed to work in Aden, also killing two soldiers escorting him. It identified the bomber as a Somali national but gave no other details.

Al Qaeda in the Arabian Peninsula is believed to be the most active branch of the global network and has plotted a number of botched attempts against US targets.

As government control waned during last year’s popular protests that ousted president Ali Abdullah Saleh, the Al-Qaeda-linked Ansar Al-Sharia seized a number of towns in Abyan province including Jaar, Zinjibar and Shaqra.

US officials say President Abd-Rabbu Mansour Hadi, who came to power in February, is more cooperative in the fight against Islamist militancy than his predecessor was.