At least 30 rebel Houthi fighters have been killed in renewed clashes in the northern Yemeni city of Saada.
Four Yemeni soldiers were also killed in Sunday's fighting, Al Jazeera’s correspondent in Yemen quoted security sources as saying.
The Houthi fighters from the Zaidi sect of Shia Islam are concentrated mainly in the Saada and Amran provinces.
They are known as Houthis after their late leader Hussein Badr Eddin al-Houthi, who was killed by the Yemeni army in September 2004. The fighters are now led by his brother Abdul-Malek al-Houthi.
The Zaidis are a minority in mainly Sunni Yemen but form the majority in the north.
Five weeks of fighting has led to the unfolding of a humanitarian crisis among the tens of thousands of civilians forced to flee from their homes, according to relief groups.
The United Nations has estimated that about 150,000 people have been displaced by instability in Saada province since sporadic fighting broke out in 2004.