But the terrorist group, known as al Qaeda in the Arabian Peninsula (AQAP), now claims the attack was an attempt to take out the U.S. command node in Mukalla and hamper American drone strikes in the country.
That said, militant leaders within the Yemeni cell pledged to carry out more attacks against similar targets inside the country being used by American and allied forces to "direct the war against the Mujahideen and operate pilotless planes," Reuters reported on Monday.
"Such joint security targets, which participate with the Americans in their war on the Muslim people, are a legitimate target for our operations, and we will puncture these eyes that the enemy uses," according to a statement issued by AQAP leaders shortly after the attempted strike.
Sanaa denied the Mukalla base was ever used by U.S. military or intelligence to coordinate armed drone strikes inside the country.
The command and control center was used exclusively by the Yemeni military to coordinate counspiracy operations off the country's southeastern coast.
The only kinds of missions ran out of that command center were focused on "securing [sea] shipping routes in the Arabian Sea," a Yemeni official told Reuters on Monday.
The group's attempt to overrun the Yemeni military base in Mukalla was part of a larger plot to take over several cities in and around Hadramaut, which is the ancestral home of al Qaeda leader Osama bin Laden.
Since that attempted AQAP offensive, Washington and Yemen have ratcheted up counterterrorism operations in the country, launching multiple drone strikes against suspected terrorist targets in the Mideast and North Africa in the weeks after the attacks.
American airstrikes have killed more than 30 AQAP fighters since August, including senior al Qaeda member Saleh Jouti.
That month, American unmanned aircraft killed 12 Yemeni militants in the Wadi Ubaidah district, roughly 100 miles east of Sanaa, and the al-Qutn area of Hadramawt province in a day-long series of drone strikes in the country.