Aden, April 3 (IANS): An Al Qaeda affiliate claimed responsibility Thursday for the attack on the army headquarters in Yemen's southern port city of Aden.

The Al Qaeda in the Arabian Peninsula (AQAP) based in Yemen posted a statement on Islamic websites, claiming it conducted Wednesday's assault to "strike at the US drone programme and the joint operation rooms that target AQAP leaders and operatives", Xinhua reported.

The statement warned the military authorities not to cooperate with Americans in the war against Al Qaeda, saying the attack was "only a message which will be followed by others".

Two coordinated attacks that targeted the headquarters of the Fourth Military Region in Aden early Wednesday killed 16 people and injured dozens of others including civilians and passers-by.

Fierce clashes that followed the attack left about six militants, five soldiers and five civilians dead, including women and children.

Scores of masked attackers from the Al Qaeda-affiliated group stormed the army headquarters in the coastal district of Tawahi.

Militants of the Yemen-based Al Qaeda offshoot were blamed by the country's government for a series of assassinations and armed attacks, mostly in the country's southern regions.