The U.S. military launched an airstrike against Yemen’s al-Qaeda affiliate early Tuesday, targeting an area of the country where the group is increasingly asserting its influence.

At least a dozen people were killed in the strike, including insurgents from al-Qaeda in the Arabian Peninsula — also known as AQAP — and local militants, according to some reports. Other accounts put the death toll at about half that number.

Abdul Monem al-Fahtani, said to be a mid-level AQAP leader, was reportedly among the dead. Fahtani is believed to have participated in the 2000 al-Qaeda suicide attack on the USS Cole, which left 17 American sailors dead. Wanted by the Yemeni government, he was the target of an attack by Yemeni forces in late 2010, although his death was never confirmed.

A high-ranking Yemeni security official said Fahtani’s death in the Tuesday strike could also not be confirmed. Two separate attacks hit a school where militants had gathered for a meeting late Monday and a vehicle nearby, said the official, who was not authorized to speak to reporters.

The strike was carried out by the Joint Special Operations Command, which operates alongside the CIA in Yemen. It was unclear whether it involved unmanned drones, cruise missiles or piloted aircraft. All have been used in attacks in the country.

The strike follows a lull in U.S. air attacks in Yemen after the death of Anwar al-Awlaki, an American-born radical cleric and AQAP leader who was killed in a drone strike in September.

Administration officials have expressed concern over the expansion of Islamist extremists, many with links to AQAP, into Abyan province in southern Yemen. The militants, who have taken advantage of the political turmoil unleashed by Yemen’s populist uprising, control large swaths in the province.

Some analysts have speculated that AQAP has at least temporarily shifted its focus from international terrorism to domestic goals in Yemen, joining forces with other militant groups to claim a geographic base from which to attack the government.

But a U.S. official, speaking on condition of anonymity to discuss intelligence issues, said AQAP “hasn’t changed its two main aims, which are to attack the West while undermining the government of Yemen to solidify their safe haven there. They may have more success at the latter if they continue to take advantage of the political unrest there, which is going to be tense for some time.”

Although the U.S. military took the lead in Tuesday’s strike, the CIA, which is seen as more effective in building human intelligence networks, has taken a more prominent role in Yemen operations in recent months, said a former U.S. official with knowledge of the operations.

In the wake of the Awlaki killing, there has been a significant slowing in drone strikes in Yemen, in part because AQAP leaders have become more disciplined in their actions — relying on couriers instead of cellphones, for example, and not returning to the same places, the former official said.

Yemen has become a template for growing CIA and JSOC counterterrorism collaboration. Unlike in Pakistan, where the CIA has had sole responsibility for hundreds of drone strikes against alleged insurgent safe havens in the tribal regions along the Afghan border, both the CIA and the military have participated in the Yemen strikes.

The CIA’s drone strikes in Pakistan have been far more extensive, and more controversial, than the operations in Yemen.

Staff writer Greg Jaffe and special correspondent Ali Almujahed in Yemen contributed to this report.