Yemen: Tribal fighters clash with security forces
About 100 armed fighters loyal to a tribal leader in Yemen have clashed with security forces on the northern outskirts of the capital, Sanaa.
Tribal leaders say hundreds more are marching towards the city in support of their leader, Sheikh Sadiq al-Ahmar.
President Ali Abdullah Saleh is refusing to step down despite months of opposition against his 33-year rule, as Lina Sinjab reports.