ADEN, Yemen - Some 54,000 Yemenis have fled the flashpoint southern province of Abyan since militants took over its capital last month, a government official said on Sunday, as fighting intensified in the area.
Mass protests demanding an end to President Ali Abdullah Saleh's three-decade rule and a political impasse continue to paralyse Yemen, as he recovers in Riyadh from an assassination attempt.
His government risks losing control of swathes of the country and giving al Qaeda's local wing a foothold next to key shipping routes.
The flight of thousands of people from the southern violence, as well as severe food and water shortages, raise the spectre of a humanitarian crisis in a country already on the verge of collapse.
A government official in charge of refugee affairs told a UN delegation visiting Yemen that tens of thousands had fled from Abyan to neighbouring Aden, a port near a strategic sea lane through which ships carry some 3 million barrels of oil daily.
In the past few months, militants have seized two Abyan cities as well as a military base and are fighting the army to try to capture another base outside the provincial capital.
A local official said 13 militants and six soldiers were killed in fresh clashes on Monday around the base. Troops sent a plea for help on Sunday, saying they had been under siege for over a month.
"The 25th brigade fighting outside of Zinjibar will continue fighting until the last shot, despite the difficult conditions it is facing, including lack of supplies and human reinforcements," the official told Reuters by telephone.
Officers in the 25th brigade have said they are in dire need of troops, weapons and water.
The official on Monday blamed higher military authorities for troops' inability to gain ground against militants, saying warplanes were striking the wrong targets: "They're bombing areas unrelated to the clashes, where there are no armed men hiding out."
The president's opponents accuse him of deliberately letting militants tighten their grip on the country to prove to neighbouring oil giant Saudi Arabia and Western governments that only he stands in the way of an Islamist militant takeover.
Local efforts to mediate the crisis have also failed.
A powerful southern tribal leader in Abyan, Sheikh Tareq al-Fadli, tried to bring together representatives from the army and militants on Monday, but tribesmen who attended said neither party had sent envoys.
(Writing by Isabel Coles; editing by Andrew Roche)