Al Qaeda fighters captured the capital of a province in southern Yemen, killing about 20 soldiers, while the United States is evacuating its remaining 100 special operations forces from Yemen, amid a deteriorating security situation in the country. The fighting came hours after suicide bombers killed 137 people in the national capital Sanaa, in coordinated attacks claimed by Islamic State, an offshoot of al Qaeda that controls swathes of Syria and Iraq. Clashes also took place in the country's north on Friday between local tribes and the Houthi militia, which controls Sanaa, illustrating the wide-ranging nature of Yemen's security crisis. AQAP fighters captured al-Houta, capital of the southern Lahj Province, on Friday but were forced to withdraw after holding it for several hours, the officials and residents said. Two army brigades then entered the city. There were no reports of any militant casualties. Houta is only 30 km (20 miles) from the Indian Ocean port of Aden, where President Abd-Rabbu Mansour Hadi has temporarily based the government since he escaped from weeks of house arrest in Sanaa by Houthi militia. In the past two days, unidentified warplanes have bombed the palace in Aden that Hadi has been using. The clashes in the north on Friday took place on the borders of Marib and al-Baydha provinces, a government official said, but there were no immediate reports of casualties. Meanwhile in Taiz, a mainly Sunni city in southern Yemen, Houthi forces on Saturday fired on hundreds of people protesting against their advance across the country, but there were no immediate reports of casualties. The Interior Ministry, which is dominated by Houthis, denied it had sent security forces to Taiz to help quell unrest.Some political analysts say the Houthi advance could drive Yemeni Sunnis to align with al Qaeda and Islamic State. Meanwhile, the United States is evacuating its remaining 100 special operations forces from Yemen, CNN reported, citing sources in the region familiar with the matter. CNN said the troops, who had conducted counterterrorism operations against al Qaeda and its affiliated militant groups, were the last U.S. forces stationed in Yemen. The United States closed its embassy in Sanaa last month, after Houthi rebels took over the Yemeni capital. .