A drone strike killed a suspected Al-Qaeda militant in southern Yemen, a security official said on Thursday, as the US steps up its air war against the jihadists.

The missile hit Al-Qaeda provincial official Ahmed Ali Saana as he was riding a motorbike late on Wednesday in the town of Khabar al-Muraqasha in Abyan province, a major target of recent drone strikes, the official said on condition of anonymity.

The Pentagon has confirmed more than 70 air strikes on Al-Qaeda targets in Yemen since February 28.

Yemeni security officials have reported dozens of suspected jihadist fighters killed in the strikes on Abyan and the neighbouring provinces of Shabwa and Baida.

More than two years of civil war in Yemen between government forces and Shia rebels who control the capital have created a power vacuum which Al-Qaeda has exploited to consolidate its presence.

A commando raid against Al-Qaeda in Baida province was the first operation US President Donald Trump ordered after taking office in January.

It went badly wrong, resulting in the deaths of a US Navy SEAL and multiple civilians, including women and children, the Pentagon acknowledged.

Last month, Trump reportedly gave the Central Intelligence Agency new powers to authorise drone strikes against extremist targets in the Middle East independently of the Pentagon.