THOUSANDS of panicked civilians fled heavy fighting in the Yemeni capital Sana'a yesterday amid growing fears that President Ali Abdullah Saleh's refusal to stand down could trigger a civil war.
Britain and the US have urged all their nationals to leave Yemen and most American diplomats were evacuated. Britain has reduced embassy numbers "to a level sufficient only to work on the most pressing and vital British national interests in Yemen".
For much of the day the city echoed to the crump of exploding mortar shells and bursts of machine gun fire as troops loyal to Mr Saleh clashed with militiamen controlled by Sadiq al-Ahmar, a tribal chief and former ally.
Up to 40 people were killed, bringing the death toll to more than 100 since Sunday, when Mr Saleh reneged on a pledge to stand down for a third time.
Yemen is facing the prospect of a deadly conflict between the remnants of his army and tribal militias once held in check by the president's effective but corrupt system of patronage.
Several government ministries have fallen to Mr Ahmar's fighters, while the president has retaliated by ordering his troops to attack a television station owned by his rival. As gunmen roamed the streets, residents fled.
G8 leaders meeting in France called for calm, but made it clear that they blamed Mr Saleh for the fighting after his persistent refusal to sign a deal to hand power to his deputy within 30 days in exchange for immunity from prosecution.
Mr Ahmar,leader of the powerful Hashed tribal confederation, accused him of launching an attack on his mansion in northern Sana'a on Monday.
"He is the one who started this war," Mr Ahmar said. " He wants to explode the situation. He is sending a message to the world: 'Look if I leave, this is the kind of war that will take place'."
Mr Saleh is Mr Ahmar's kinsman. But the two fell out after the latter joined a massive defection to the opposition as protests calling for the president's resignation increased.
For three months, hundreds of thousands have joined daily rallies urging the president to go -- a civilian movement that is in danger of being overshadowed as a more familiar power struggle on tribal lines begins. (© Daily Telegraph, London)