The conflicting accounts, however, did not differ on the death count, which raised the overall toll to at least 109 since intense clashes broke out Monday in the heart of Yemen’s capital. The battles threaten to tip Yemen into a civil war-style showdown after months of street protests seeking to end Saleh’s 32-year rule.

The escalating violence prompted the State Department on Wednesday to order nonessential U.S. diplomats and their families to leave the country.

Yemen’s Defense Ministry said the latest deaths occurred in an explosion at a weapons storage facility in a western part of Sanaa. The opposition, however, said shells slammed into a residential building occupied by fighters loyal to Sheik Sadeq al-Ahmar, the leader of the Yemen’s largest and most powerful tribe.

Al-Ahmar’s tribe, called the Hashid, turned against Saleh two months ago but had kept its well-armed militia on the sidelines. The Hashid and allied tribes opened fierce attacks Monday after Saleh’s forces tried to storm al-Ahmar’s compound in central Sanaa.

Al-Ahmar’s forces have laid siege to at least nine government ministries and government troops have responded with mortars and shelling. Yemeni authorities also escalated its campaign against al-Ahmar by issuing an arrest warrant against him and other tribal leaders.

Speaking to the pan-Arab broadcaster Al-Jazeera by phone, al-Ahmar accused Saleh of “dragging the country to a civil war” and urged neighboring Gulf countries and other nations to force Saleh to leave power or risk pushing the country into civil war.

“Go, leave, step down,” al-Ahmar urged Saleh. “This is a war between Saleh and all Yemenis. Those killed are the sons of Yemen.”

Al-Ahmar offered a cease-fire if Saleh takes the first steps to halt the attacks, which he said have spread farther throughout the capital to include areas around the airport.

But Saleh has struck a tone of hard-line defiance.

On Wednesday, he vowed he would not step down or allow Yemen to become a “failed state” and haven for al-Qaida.

“I will not leave power and I will not leave Yemen,” said a statement read by Saleh’s spokesman. “I don’t take orders from outside.”

Saleh also threatened that his ouster could turn Yemen into a haven for al-Qaida — directly touching on U.S. fears that chaos in Yemen could open room for more terrorist footholds. The Yemeni branch of al-Qaida is linked to the attempted Christmas Day 2009 bombing of an airline over Detroit and explosives found in parcels intercepted last year in Dubai and Britain.

“Yemen will not be a failed state. It will not turn to al-Qaida refuge,” the statement said. Saleh also said he would work to prevent the recent violence from “dragging the country into a civil war.”

President Barack Obama has called on Saleh to transfer power — a change from an administration that once considered the Yemeni ruler a necessary ally against terrorism.

In Washington, a State Department advisory warned the clashes in Yemen’s capital “may escalate without notice.”

“The security threat level in Yemen is extremely high due to terrorist activities and civil unrest,” the advisory said. “There is ongoing civil unrest throughout the country and large-scale protests in major cities.”

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Associated Press writer Maggie Michael in Cairo contributed to this report.

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