Sanaa, Yemen:  Two Shi'ite Muslim Houthi tribal fighters and a Yemeni soldier were killed on Saturday in renewed clashes in the northern province of Amran, local officials told Reuters.

A group of armed Houthi fighters marched to the city of Amran early on Saturday and demanded to be allowed to stage a demonstration, but fighting broke out when the army refused to let them enter the city, an official in Amran told Reuters.

Last week, Houthis managed to hold an anti-government protest in Amran.

"The Houthis have staged these protests fully armed, that's why the army forces had to stop them from entering the city this time," said an official.

Fighters loyal to the Shi'ite Houthi tribe, who have repeatedly fought government forces since 2004, are trying to tighten their grip on the north as Yemen moves towards a federal system that gives more power to regional authorities.

Last week at least 40 people were killed in clashes between Houthis and Sunni Muslim tribesmen near Sanaa.

Mediators have been trying to persuade the warring parties to retreat from their positions, which would be taken by government soldiers, but so far without success.

Gulf Arab states and the United States are concerned about violence in the Western-allied country as it is home to a wing of al Qaeda, shares a long border with top oil exporter Saudi Arabia and its coast runs alongside major shipping lanes.

-Reuters