SANAA, March 13 (Reuters) - Two Yemeni soldiers were killed on Thursday when Shi'ite Muslim Houthi tribal fighters attacked an army base near the capital Sanaa, military sources said.
Another four soldiers were injured in the attack, the sources added, as sectarian fighting that flared up in October in the north spread closer to Sanaa.
Four Houthi rebels were also injured, they said.
Yemen deployed soldier to the northeastern part of the capital this week after at least 40 people were killed in clashes between Houthis and Sunni Muslim tribesmen.
Mediators have been trying to persuade the warring parties to retreat from positions they were holding near Sanaa and replace them with government soldiers but without success yet.
Fighters loyal to the Shi'ite Houthi tribe, who have fought government forces since 2004, are trying to tighten their grip on the north as Yemen - home to one of al Qaeda's most active branches - moves towards a federal system that gives more power to regional authorities.
Gulf Arab states and the United States are particularly concerned about violence in the Western-allied country as it shares a long border with top oil exporter Saudi Arabia and its coast runs alongside Red Sea and Gulf of Aden shipping lanes. (Reporting by Mohamed Ghobari; Editing by Sami Aboudi and Alison Williams)