Air raids struck Al-Qaeda elements in southern Yemen overnight and killed 15 people, including a long-hunted militant leader, tribal chiefs said, adding that extremists responded by killing two soldiers on Tuesday.
The four Monday night raids were "carried out by US planes," according to a local military official who spoke on condition of anonymity. They hit targets in the Loder and Al-Wadih areas of Abyan province, a tribal chief said.
Al-Qaeda militants control much of the province after taking advantage of months of political turmoil, which has forced President Ali Abdullah Saleh to agree to step down next month, to overrun swathes of the south.
"We think they were carried out by American planes," a tribal chief said, speaking on condition of anonymity.
Three of the raids targeted a school in which Al-Qaeda fighters and chiefs of a local militant network were meeting around midnight, the sources said.
Around a dozen people were killed, among them regional Al-Qaeda leader Abdul Monem al-Fathani, who has long been sought by the Yemeni authorities, they said.
The fourth strike hit an Al-Qaeda control post, killing three more people, they said.
"All those killed are Al-Qaeda militants," a tribal chief said.
Witnesses told AFP they saw "charred" bodies of al-Qaeda militants taken out of the school.
Twelve wounded members of the extremist network were also taken to two hospitals in the area, the same sources said.
"Two planes carried out these raids and continued to fly over the region through the night," another tribal chief told AFP.
Hours later, Al-Qaeda militants killed two soldiers on the outskirts of Rada, 130 kilometres (80 miles) southeast of Sanaa. The town was seized by more than 1,000 Al-Qaeda fighters and held for nine days in mid-January in what was seen as a significant advance towards the capital.
"Two soldiers were killed and several others were wounded in an attack on an army checkpoint by supporters of Tarek al-Dahab," brother-in-law of the Yemeni-American extremist Anwar al-Awlaqi, who was killed in a US air strike last September, tribal chiefs said.
Dahab had led the fighters who bowed to tribal pressure and withdrew from the town after authorities pledged to free 15 militants. They refer to themselves as the Partisans of Sharia (Islamic law).
An official in Rada confirmed the deaths of two soldiers in the fighting which he said has been ongoing since the early morning hours.
The deteriorating security situation in Yemen, caught up in an Arab pro-democracy uprising unleashed a year ago, has raised alarm including at the UN Security Council of a growing presence of Al-Qaeda militants in lawless areas in the south and east of the country.
The New York Times reported in June that the United States had stepped up its attacks on militant suspects in Yemen with armed drones and fighter jets.
The southern Arabian Peninsula country is the ancestral homeland of Al-Qaeda's late founder Osama bin Laden, who was killed in May in a US raid in Pakistan.
It has been the scene of several attacks claimed by the group on embassies, tourist sites and oil installations.
The rugged terrain of Yemen, which stretches over 529,000 square kilometres (204,248 square miles), provides ideal cover for armed groups.
Saleh is in the United States for medical treatment after being seriously wounded in a bombing at the presidential palace in June.
In November, after 10 months of bloody protests, he signed a deal by which he transferred constitutional powers to his deputy, who is the sole candidate for next month's presidential polls.