US forces killed dozens of Islamic State (IS) group militants in a strike on Monday on two training camps in Yemen, the Pentagon said.

The camps in the central al-Bayda province were being used to train new fighters using AK-47s, machine guns and rocket-propelled grenade launchers, the Pentagon said in a statement.

IS has used ungoverned areas in Yemen to plot, direct, instigate and recruit for attacks against America and its allies around the world, it said.

The United States also considers the Yemen-based al-Qaeda in the Arabian Peninsula (AQAP) to be the militant group's most dangerous branch.

A long-running drone war against AQAP and IS has intensified since US President Donald Trump took office in January.

An air raid he ordered that month killed several Yemeni civilians and a US Navy SEAL in al-Bayda province.

AQAP and IS have flourished in the chaos of the country's civil war, which pits the Saudi-backed government of President Abd Rabbuh Mansour Hadi against Houthis.

More than 8,000 people have been killed since a Saudi-led coalition joined the Yemen war on Hadi's side in 2015.

AQAP and IS operate in several provinces in south and central Yemen, including in Abyan, Shabwa and al-Bayda.

-Agencies