Officials in Yemen's second-largest city say gunmen have killed four soldiers near the presidential palace. Officials say one of the attackers was also killed in the violence Sunday in Taiz.

The assault comes a day after Yemen's authoritarian president left the country to receive medical treatment in Saudi Arabia.

Thousands of anti-government protesters in Sana'a on Sunday celebrated President Ali Abdullah Saleh's departure. They are hoping that Mr. Saleh's departure is permanent, bringing an an end to his 33-year reign.

Yemeni Vice President Abed Rabbo Mansour Hadi met with U.S. Ambassador Gerald Feierstein Sunday, a strong indicator that Hadi is in charge since the president's departure. U.S. officials also say President Barack Obama's national security adviser, John Brennan, spoke with Hadi Saturday.

President Saleh, along with at least four other high-ranking officials, flew to neighboring Saudi Arabia Saturday after they were wounded in an attack Friday on the presidential compound in Sana'a.

However, several things remain unclear in the rapidly changing situation in Yemen – the extent of Mr. Saleh's injuries and whether he intends to return, and if any of his sons or nephews stayed behind to try to keep a grip on power.

Yemeni government officials and rebel tribesmen agreed to a new cease-fire Saturday brokered by Saudi Arabia.

Representatives of both sides said they will accept the plan. Just a week ago, a similar truce quickly collapsed in renewed fighting between President Saleh's forces and loyalists to an opposition tribal leader, Sheikh Sadiq al-Ahmar.

Nearly 400 people have been killed since the popular uprising against Mr. Saleh began in January.