Shiite Huthi rebels clashed Monday with Yemeni army forces and loyalist tribes northeast of Sanaa as a UN envoy kept up mediation efforts, tribal sources said.
Fierce gunfights erupted when rebels attacked troops and armed tribesmen in the flashpoint Al-Ghayl district of Jawf province, tribal sources said.
The attack was in attempt to regain control of areas seized by the army, they said.
A tribal chief said scores of fighters were killed or wounded in the clashes, but AFP could not verify a death toll.