The source, who requested anonymity, said that tribesmen attacked a Houthi checkpoint in the center of the eastern province.
Four people – three Houthi members and a tribesman – were killed in the ensuing clashes, he added.
Three other people were wounded in the clashes, the source said.
The Houthi group, which seized Yemeni capital Sanaa in September of 2014, has so far been unable to control the oil-rich Maarib province.
