The assault by the tribesmen on the Republican Guards' base at Dahrah took place early Monday. The Defense Ministry said in a statement that base commander Brig. Ali Al-Keleibi was killed in the fighting.
The officials said the tribesmen captured 30 guards when they seized control of the facility. At least four tribesmen were killed and 27 wounded in the fighting.
It was the second Republican Guards' base to be captured in a week. Protesters backed by renegade soldiers overran a base belonging to the guards last week in Sanaa as the opposition stepped up its campaign to oust President Ali Abdullah Saleh.
The Yemeni leader is under tremendous pressure from street protesters, neighboring Arab states and the United States to transfer power and end the country's deepening crisis, which has killed hundreds since anti-government demonstrations began in February.
Al-Qaeda-linked fighters have already taken advantage of Yemen's unrest to overrun several towns in southern Yemen, expanding their range of influence beyond the country's hinterlands. In a televised address Sunday, Saleh accused his opponents of cooperating with Al-Qaeda, plotting a coup and shedding blood in an attempt to seize power.
He has also signaled an intention several times to sign a US-backed deal to step aside in exchange for immunity from prosecution only to back out at the last minute.
In Sunday's address, Saleh said he was committed to the deal, which was drafted by the Gulf Cooperation Council. His opponents do not trust him and believe he is stalling for time while consolidating his hold on power.
Disappointed by his speech, protesters vowed to increase the pressure on Saleh to quit. His refusal to hand over power fueled anger in Sanaa's "Change Square" where thousands have camped out for eight months demanding an end to Saleh's 33-year rule.
"His speech was about creating chaos, not solutions. There was nothing there to solve this crisis," said Abdullah Magany, a high school biology teacher, at a rally in the center of the rows of ramshackle tents that are the heart of the protest movement. "We need to keep escalating our protests."
