Yemen's Shiite rebels say they have pulled out of northern city seized earlier this month

Yemen's Shiite rebels battling their conservative Sunni rivals from one of the country's largest tribes have pulled out of a northern city they captured earlier this month, the rebels' spokesman said Friday.

The spokesman, Mohammed Abdul-Salam, said the Hawthi rebels handed over the provincial capital of Amran to the central government, reflecting a military loss for their rivals, the powerful Hashid tribesmen who had previously controlled the city.

The sectarian and tribal fighting between the two sides has raged in the city and the province of Amran for weeks, leaving scores killed and forcing many families to flee the area. Yemeni Red Crescent estimated that 15,000 families had fled the fighting.

On July 8, the Hawthis overran Amran, 72 kilometers (45 miles) from the Yemeni capital, Sanaa, defeating the Hashid and an army unit allied with the Sunni tribe.

The United Nations subsequently demanded an immediate pullout of all tribal fighters from the city. Yemeni President Abed Rabbo Mansour Hadi sacked two top military commanders who were part of the army unit that backed the Hashid. The president also paid a surprise visit to Amran this week, urging people to return and saying the city was "peaceful and safe."

The Hawthis had waged a six-year insurgency in the north against Hadi's predecessor, Ali Abdullah Saleh, which officially ended in 2010.

But fighting has reignited at times. The Hawthis have fought ultraconservative Islamists in several northern cities and towns, accusing them of turning their strongholds and cities into incubators of Sunni extremism. The Hashid, who have often played a kingmaker's role in Yemeni politics, also have a strong alliance with Yemen's branch of the Muslim Brotherhood, whose fighters fought on the side of the Hashid in Amran.

Attempts at lasting cease-fires have repeatedly failed.

Yemen, the poorest Arab nation, is facing multiple challenges.

In addition to the presence of the world's most dangerous al-Qaida offshoot in much of its lawless hinterland and several cities, Yemen faces a secessionist movement in the south and the Hawthi rebellion in the north.