Clashes in Yemen close capital's airport
Air passengers in the Yemeni capital, Sanaa, have reported that their flights out of the country have been suspended.
It is another indication that what began as a popular uprising, part of the so-called Arab Spring, is now something altogether more sinister.
The latest fighting, in which dozens have been killed and injured overnight, pits forces loyal to the embattled president Ali Abdullah Saleh against fighters of the country's most powerful tribe.
The BBC's Lina Sinjab said around a hundred people were involved in the fighting.