Two apparent US drone attacks have killed at least 10 suspected al-Qaeda-linked fighters in Yemen, while Yemeni government forces killed 15 others in a new offensive against the armed groups, local and military officials said.
The air strikes destroyed three vehicles in the eastern oil-producing Maarib province and near the border of the southeastern Shabwa province, the defence ministry website said on Sunday, without elaborating.
Yemen and Washington do not acknowledge US drone attacks, but local officials told the Reuters news agency that the strikes were believed to have been carried out by US drones against the Yemen-based al-Qaeda in the Arabian Peninsula (AQAP), with those killed including an Egyptian and two Saudis.
It was the latest in a series of reported drone attacks on fighters in the south of the impoverished Arab country who exploited mass protests last year against then-President Ali Abdullah Saleh to seize large swathes of territory, including Zinjibar, the capital of restive Abyan province.
Last week, the US defence department said Washington had resumed training Yemeni armed forces to bolster the fight against al-Qaeda, after a suspension during the political upheaval that ousted Saleh.
Residents said Yemeni air force planes dropped leaflets on Saturday urging civilians to leave areas held by armed groups targeted by the army offensive, prompting a mass exodus from parts of Abyan.
Fifteen armed men as well as five soldiers and an army officer were killed in fighting on Saturday, a military official who did not want to be identified told Reuters.
"A force of about 20,000 men is taking part in this offensive, ordered by President Abd-Rabbu Mansour Hadi to free the cities of Zinjibar and Jaar," he said. Navy units would also be used in operations along Abyan's coast on the Gulf of Aden.
Yemen's fractured state and dysfunctional security apparatus have provided al-Qaeda's regional wing with a suitable breeding ground for bomb plots on Western targets.
In a sign of growing lawlessness after more than a year of unrest, Bulgaria's ambassador to Yemen escaped with minor injuries on Saturday after masked men opened fire on his car in the capital and tried to kidnap him, a Western diplomat said.
US officials said this week they had thwarted a plot by AQAP to arm a suicide bomber with a non-metallic device, an upgraded version of the "underwear bomb" carried onto an airliner on Christmas Day 2009.
AQAP has plotted overseas attacks that have been prevented but raised major concern for Washington, which is trying to wipe out suspected AQAP operatives with the drone and missile strikes.
Tribal leaders in parts of Yemen where the drone attacks have killed civilians say the air strikes are turning more and more people against the government and the US.
Yemen's army, which split into two factions during the uprising that eventually unseated Saleh, has been battling to get the upper hand against the armed group.
In March, the UNHCR, the UN refugee agency, warned that Yemen was facing a new wave of internal displacement as tens of thousands of civilians fled tribal clashes in the north and fighting with armed groups in the south.
Hadi, who had been Saleh's vice-president, was elected unopposed in February under a US-backed power transition plan brokered by Yemen's Gulf neighbours to end the political turmoil.