Yemeni government forces and fighters loyal to tribal leader Sheik Sadeq al-Ahmar continue to exchange heavy gunfire in the capital, Sana'a, battling for control of key positions as more foreign diplomats leave the impoverished, war-torn country.

The fighting in Sana'a raged until dawn Wednesday and continued in bursts throughout the day. Medical officials and witnesses tallying deaths say at least 41 people from both sides were killed in the battles.

The clashes have engulfed the northern Hasaba neighborhood, where tribal fighters seized a number of government ministries and buildings. Loyalist artillery fire has heavily damaged the compound of al-Ahmar, the strongest rival to President Ali Abdullah Saleh, and the government cut the area's electricity and water supplies.

Mr. Saleh's forces also used mortars and rocket-propelled grenades Wednesday to attack the headquarters of Brigadier General Ali Mohsen al-Ahmar, the country's most powerful military leader.

General Mohsen defected to the opposition in March. He is from the influential Hashid tribe, along with al-Ahmar, whose fighters last week joined a nearly four-month anti-government uprising to force Mr. Saleh from power.

The fighting has caused a number of countries to close or scale back their diplomatic missions. Kuwait said Wednesday it had evacuated its embassy staff, joining Italy, Qatar and Germany in suspending operations in Yemen. The U.S. last week moved most non-essential staff out of the country.

U.S. Secretary of State Hillary Clinton said Wednesday that Mr. Saleh's refusal to step down is prolonging the crisis. She told reporters in Washington “we cannot expect this conflict to end unless President Saleh and his government move out of the way.”

Battles have been raging on several fronts in Yemen.

The southern city of Taiz remained in lockdown Wednesday, with Republican Guard troops patrolling the streets. Earlier this week, security forces brutally dispersed anti-government protesters from the square they had occupied since February. At least 25 people have died in Taiz over the past few days.

Yemeni troops are also continuing to battle militants for control of the southern city of Zinjibar, which was seized by hundreds of Islamist fighters on Sunday.