SANAA, Yemen (AP) -- An airstrike killed nine al-Qaida fighters Wednesday in southern Yemen as the military maintained pressure on the terror group a day after government troops backed by armed tribesmen recaptured two militant strongholds, officials said.

The military officials said the strike destroyed a car parked near a house in the town of Azan in Shabwa province, an al-Qaida stronghold. They said the missile was believed to have been fired by a drone.

Al-Qaida's propaganda arm known as Madad claiming in an email message that the attack was launched by a U.S. drone. The Internet-based agency is known to be close to al-Qaida's Yemen branch.

The officials spoke on condition of anonymity in line with army regulations.

A monthlong government offensive in the south, orchestrated by U.S. military advisers and bankrolled by neighboring Saudi Arabia, succeeded in driving the militants from two towns in Abyan province - Jaar and the provincial capital Zinjibar. The militants had held the two population centers for more than a year.

The group, however, remains in control of a handful of towns, with hundreds of its members scattered in the mountains, valleys and vast desert of the Arab world's most impoverished country.

The officials said some militants who fled Jaar have taken refuge in Azan.

The militant group said it retreated to "spare bloodshed," threatening to retaliate by attacking Yemen's capital, Sanaa. In an emailed statement, the group addressed the Yemeni leadership as "crusaders and American agents" and warned "we will chase you in your cities and palaces."

Tuesday's success capped weeks of fighting as Yemen's new President Abed Rabbo Mansour Hadi has pledged to uproot al-Qaida from the south with help from the United States as part of a new cooperation following Ali Abdullah Saleh's ouster.

With the capture of Jaar and Zinjibar, Yemen's new U.S.-backed leadership now has to deal with another fight in its war against al-Qaida: sleeper cells, which are hard to chase.

Brig. Gen. Mohammed al-Sawmali said Tuesday's successes ended al-Qaida's aspiration to establish Islamic rule in the south but not its presence in the country.

"We expect the group to carry out selective operations targeting key political and military figures," al-Sawmali said Tuesday, speaking from the governor's office in Zinjibar, which al-Qaida had turned into a command center.

The U.S. considers al-Qaida's Yemen branch to be the terror network's most dangerous offshoot.

The group took advantage of a security vacuum last year amid a popular uprising against Yemen's longtime leader, Ali Abdullah Saleh, to seize major swaths of territory in the strategic south. That raised fears it could use the area as a foothold to launch more attacks on U.S. targets.

Yemen's al-Qaida offshoot, known as the al-Qaida in the Arabian Peninsula, has been blamed for directing a string of unsuccessful bomb plots on U.S. soil from its hideouts. It also emerged last month that the CIA had thwarted a plot to down a U.S.-bound airliner using a new, sophisticated explosive to be hidden in the bomber's underwear. The planned bomber was actually a double agent who turned the device over to the U.S. government.

The U.S. is helping the Yemenis from a command center manned by dozens of U.S. troops in the al-Annad air base in the southern desert, not far from the main battle zones. The Americans are coordinating assaults and airstrikes, and providing information to Yemeni forces while Saudi Arabia, the oil-rich Gulf country, has come forth with cash - especially to armed civilians who back up the Yemeni army in its battles against al-Qaida.