The defense ministry said 30 people died during airstrikes in Azzan, but didn't say whether all of the deaths were from airstrikes by unmanned aircraft or by Yemeni forces conducting airstrikes in the area, CNN reported.
Officials said no senior al-Qaida leaders died in the attack.
Militants fled to Azzan, in Shabwa province, after they lost control of Abyan province Tuesday, officials said.
"Azzan is where we expect the militants to seek shelter after the fall of Jaar [in Abyan province]. It's their last stronghold in Yemen," a senior security official said.
Yemeni security officials said at least 14 U.S. drone strikes were conducted in the past two days over both provinces. One targeted the convoy of Jalal Beleidi, a key commander of the Ansar al-Sharia militant group, who escaped unharmed, the officials said.
Yemeni forces are patrolling major towns in the region, searching for militants, witnesses said. Hundreds of troops were being dispatched to Jaar to ensure it doesn't return to militant control, defense, officials said.