At least 10 Yemeni soldiers were killed in renewed fighting in Yemen, military sources told AFP, despite diplomatic efforts to halt the long-running war in the Arab world's poorest country.
The clashes took place in oil-producing Marib province, one of the main battlegrounds and the scene of sporadic fighting even during a lull in hostilities over the past year.
Iran-backed Houthi rebels attacked a mountainous area and have been engaged in a build-up of forces in the region, two military sources told AFP.
"The Houthis (rebels) launched an attack on hills overlooking Harib district, south of Marib, and made progress on that front, causing the displacement of dozens of families," one of the sources said, speaking on condition of anonymity.
"At least 10 soldiers were killed, in addition to an unknown number of attackers," the source added. The details of the clash were confirmed by a second military official.
The fighting comes a month after at least four soldiers were killed in the same district, and dents new optimism after Saudi Arabia and Iran, who back opposing sides in what amounts to a proxy war, agreed to restore diplomatic ties.
An exchange of hundreds of prisoners was also agreed this week and Hans Grundberg, the UN secretary general's special envoy for Yemen, has said "intense diplomatic efforts" are underway to strike a peace deal.