Nine people were killed in an attack by a force backed by the United Arab Emirates (UAE) in Yemen's Shabwah province, a Yemeni government source said.
The UAE-backed force attacked members of the Al-Saada tribe in Shabwa's Merkha directorate, the source said on condition of anonymity.
The force – Dubbed the "Shabwani Elite" – received air support from Saudi-led coalition aircrafts, the same source said.
At least seven armed tribesman and two civilians were killed in the fighting, while a number of other people – from both sides – were injured.
The Shabwani Elite is comprised of locals from Shabwa who have received training by military officers from Abu Dhabi.
Impoverished Yemen has remained wracked by violence since 2014, when the Houthis overran much of the country, including the capital Sanaa.
The conflict escalated in 2015 when Saudi Arabia and its Sunni-Arab allies launched a devastating air campaign in Yemen aimed at rolling back Houthi gains.
The ongoing violence has destroyed much of Yemen's infrastructure, including water and sanitation systems, prompting the UN to describe the situation as one of "the worst humanitarian disasters of modern times".