Tribesmen in Yemen opposed to President Ali Abdullah Saleh have said they stormed a military base on the outskirts of the capital and stolen weapons.<br /><br />Hameed Asim, a leader of the tribesmen who skirmished with troops from the Republican Guard led by Saleh's son, said tribal fighters killed several troops and lost seven of their own in a raid on the base in Arhab region north of Sanaa before withdrawing.<br /><br />The attack was the latest in a series of running battles between tribesmen and forces backing Saleh, who is clinging to power despite 10 months of protest demanding his overthrow and a slide toward civil war on the borders of Saudi Arabia.<br /><br />Meanwhile, youth activists are concerned that their protest movement is being hijacked by rival military factions and tribes.<br /><br />Al Jazeera's special correspondent, who we are not naming for her own safety, reports from Sanaa.