Five members of Yemen's pro-government forces were killed when an explosion targeted their military base in the country's southern province of Abyan on Sunday, a military official said.

The local military source said on condition of anonymity that "an explosion struck the headquarters of the 5th Infantry Army Brigade that's located in Abyan's district of Mudiyah."

He said that the explosion killed five soldiers and injured more than 40 others at the scene.

The source clarified that "the explosion that might be caused by external bombardment struck the military base while the soldiers were gathering to perform their noon prayers."

Pro-government military experts began investigating the nature of the explosion and its main causes, according to the official.

No group has claimed responsibility for the explosion at the pro-government military base.

Yemen has been mired in a civil war since late 2014 when the Houthi militia seized control of several northern provinces and forced the internationally recognized government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa.