At least 24 people were killed on Friday as Yemeni troops and allied Islamists engaged in heavy fighting with Shiite rebels in the north, tribal sources said.
The fighting, in which soldiers aided by fighters from the Islamist Al-Islah party were pitted against Zaidi Shiite rebels, was for control of local government offices in Hizm, capital of Jawf province.
"The army and Al-Islah lost eight men, while the Shiite rebels lost twice that number, and there have been dozens of wounded on both sides," one of the sources told AFP.
Earlier this month, Yemen's president and main parties agreed to transform the unrest-riven country into a six-region federation as part of a political transition.
Signup to our newsletter and follow us on Facebook and Twitter!
The rebels are apparently seeking to seize Hizm so as to be able to integrate all of Jawf into the Azal region, one of four to be created in the north, that includes their stronghold of Saada province.
But as the arrangement currently stands, Jawf would be included in the Saba region, which also includes Marib and Bayda provinces.
A tribal source said the rebels, also known as Huthis, were trying to seize the government offices as part of that effort, and that troops and the Islamists were fiercely defending the complex.
Given the resistance, the Huthis were calling for reinforcements, who were beginning to arrive, witnesses said.
Both the rebels and southern separatists have rejected the proposed federal structure, which would also create two regions in the south.
The rebels, who complain that Yemen would be divided into rich and poor regions, have already been trying to enlarge their zone of influence by pushing out from the mountains to areas closer to Sanaa.