Yemeni officials say anti-government tribesman have seized a base operated by troops loyal to President Ali Abdullah Saleh, killing a commander and capturing 30 soldiers.
The defense ministry said Monday's attack on a base north of the capital, Sana'a, killed Ali al-Keleibi, a commander in the elite Republican Guard. Officials said four tribesman were also killed in the fighting.
The head of the Organization of Islamic Cooperation on Monday urged parties in Yemen to exercise restraint and not use force against Yemeni citizens. The OIC consists of 57 member states and serves as a collective voice of the Muslim world.
On Sunday Mr. Saleh said he wants a peaceful transfer of power through elections.
He said in a televised speech he is committed to implementing a power transfer initiative drawn up by the Gulf Cooperation Council, but made no pledge to step down. The long-stalled plan calls for President Saleh to hand over power to a deputy.
The appearance was his first since he returned to the capital, Sana'a, on Friday after a three-month stay in neighboring Saudi Arabia while recuperating from a June assassination attempt.
Mr. Saleh said the elections must include presidential, parliamentary and local balloting. He also criticized his opponents for encouraging chaos, saying the country's constitution allows peaceful protests, but not robbery and destruction of state property.
Saudi Arabia's King Abdullah said the Gulf initiative is the only way to resolve the crisis, and he urged all parties in Yemen to show restraint in order to prevent more violence and killings.
Mr. Saleh's speech came just hours after Yemeni troops opened fire on a large group of anti-government protesters in Sana'a, wounding 18 people.
Witnesses say the protesters were marching near the army's headquarters when troops opened fire.
Hundreds of other protesters demonstrated in Sana'a's Change Square, which has served as a center of anti-government protests in the capital. Demonstrators prayed for protesters killed during the past week, one of the bloodiest since protests began in January.
In other violence Sunday, at least two people, including a soldier, were killed in the southern city of Taiz, and troops killed two people outside of Sana'a.
