Sanaa, Yemen (CNN) -- Fourteen troops were killed and seven others injured Saturday in an ambush of Yemen's headquarters of the intelligence service in Tawahi, Aden, the defense ministry and three local security officials said.
The militants were aboard a pickup vehicle and were attempting to storm the building, two of the officials said.
The officials are blaming al Qaeda for the attack.
"The timing for the attack was well chosen. Yemenis are preparing for Eid holiday, and al Qaeda expected the troops to be less prepared," one of the officials told CNN on condition of anonymity because he is not authorized to talk to media.
No one has announced responsibility for the attack.
The headquarters was attacked from three different fronts, the officials said.
Residents in town said four large explosions were heard in the clashes that continued for more than an hour.
All roads in Tawahi were closed and strict checkpoints were introduced.