Fears Yemen fighting may lead to 'civil war'

At least 39 people have been killed in overnight fighting as clashes intensified in the Yemeni capital, Sanaa, doctors and officials say.

Violence escalated after a ceasefire broke down between security forces and fighters loyal to Sheikh Sadiq al-Ahmar, head of a tribal confederation.

And as the BBC's Lina Sinjab reports, the conflict threatens to drag Yemen into civil war.