The number of raids launched by the US on Yemen has increased dramatically over the past week
The United States on Sunday launched a new wave of air raids against al-Qaeda in Yemen, as militants fled from towns being targeted to mountainous areas, security sources said.
At least five early morning raids hit targets linked to al-Qaeda in the Arabian Peninsula (AQAP) in the southern Shabwa and central Baida provinces, security sources told AFP.
There were no immediate reports of casualties.
Among the areas from which the radical group pulled its operatives is the Baida town of Ghail, where top AQAP commander Abdulelah al-Dhahab has reportedly been holed up, the sources said.
Suspected AQAP gunmen meanwhile killed five soldiers at a checkpoint in the southern province of Abyan, which has itself been hit by air strikes in recent days, security sources and medics there said.
Since Thursday, Washington, which regards AQAP as the militant network's most dangerous branch, has stepped up its air and drone strikes on Yemeni provinces including Baida, Shabwa and Abyan.
The Pentagon on Friday confirmed it had carried out more than 30 strikes against AQAP, conducted in partnership with the Yemeni government.
Local officials and tribal sources told AFP that at least 20 militants were killed on Thursday and Friday.
The bombing campaign comes after a botched 29 January raid against AQAP left multiple civilians - including several children - and a US Navy SEAL dead in the first military strike ordered by President Donald Trump.
Al-Qaeda has exploited a power vacuum created by two years of war between Yemen's government and Houthi rebels who control the capital to consolidate its presence, particularly in the south and east of the country.
US military strategy in Yemen has become a hot political issue after the botched commando raid in January, the first to be authorised by President Donald Trump.
Critics questioned the value of the mission, drawing a fierce rebuttal from Trump, who maintained that it had yielded vital intelligence.
After pulling out of Yemen in 2015, the US military started returning in small numbers last year to support a successful push orchestrated by the United Arab Emirates, with support from Saudi Arabia, that ejected al-Qaeda from the city of Mukalla, where it had raised tens of millions of dollars by taking over the country's third largest port.