— Clashes between government troops and gunmen in southern Yemen on Monday night gave renewed urgency to a debate among Yemeni officials over whether to push through a transitional government or wait for President Ali Abdullah Saleh to return from Saudi Arabia.

Vice President Abed Rabbo Mansour Hadi, who assumed control of the country after Saleh flew to Saudi Arabia late Saturday for treatment of wounds sustained during an attack, lobbied for the establishment of an interim “unity government,” a senior government official said. Hadi and Foreign Minister Abi Bakr al-Qirbi argued that it was time to sack Saleh, while others more loyal to the president called the proposal a “coup,” said the official, who attended the meeting and spoke on condition of anonymity to discuss confidential deliberations.

Despite those discussions, Hadi and other government officials continued to insist publicly on Monday that Saleh remains firmly in control and would return to Sanaa, the capital, in a few days.

But the United States made clear it does not wish to see its one-time ally in the fight against al-Qaeda return as president. “We think an immediate transition is in the best interests of the Yemeni people,” Secretary of State Hillary Rodham Clinton said Monday in Washington.

State Department spokesman Mark Toner added to her remarks, saying: “The time is now to begin that peaceful transition toward a democratic process.”

On Monday night, residents in the southern city of Taiz said government forces used tanks and artillery to beat back gunmen, in the latest set of clashes in a city that has been one of the epicenters of the revolt against Saleh. Medics in the city said at least four soldiers were killed and 10 anti-government personnel were wounded.

Monday’s talks about a possible transition unfolded hours after a series of fatal shootings underscored the volatility of the political impasse and the fragility of a cease-fire that some warring factions have claimed to be respecting.

Pro-Saleh gunmen opened fire on a checkpoint manned by defected soldiers of the 1st Armored Division near the vice president’s house, witnesses said. One soldier and two of the gunmen were killed. Representatives of the powerful network of tribes led by the Ahmar family, which has been fighting Saleh forces in recent weeks, said snipers in Sanaa killed three of its members.

Analysts say Saleh’s return to power appears less likely by the day. Diplomats and some opposition leaders are hoping that the wounded president will be willing to cede power under a deal proposed last month by Persian Gulf States.

While Hadi is nominally in charge of the country, the vice president is seen as a far less powerful figure than the president’s sons and nephews, who command elite military forces and remain in the country. If Saleh, 65, is pushed out in a move that his sons and regime loyalists view as a coup, the power struggle that has pushed the country close to a civil war could continue to unfold violently.

Saudi Arabia, which has bankrolled Saleh's regime as well many of Yemen’s tribes, on Monday pressed the leader to sign the agreement immediately, The Associated Press reported. After a Cabinet meeting headed by King Abdullah, the Saudi government expressed its “hope that the initiative be signed . . . to get Yemen through the crisis, preserving its security, stability and unity.”

The sense of jubilation that gripped Sanaa after Saleh’s departure spread throughout the country, as throngs took to the streets in various cities on Monday to celebrate what they saw as the end of his 33 years of autocratic rule.

Government officials, meanwhile, sought to convey that Saleh remains at the helm of the nation. The state-run news agency Saba issued a statement quoting Hadi as saying that Saleh would “return to the homeland in coming days.”

State television aired programs glorifying Saleh and featured interviews with citizens condemning Friday's rocket attack, which struck the presidential palace’s mosque during afternoon prayers.

Officials provided no new information Monday about the condition of Saleh, who underwent surgery in the neighboring kingdom on Sunday.

However, they sought to show that he was conducting some business while recovering. Saleh reportedly sent a cable to England’s Queen Elizabeth II in honor of her birthday, which some celebrate on the first Monday of June. He also sent a cable to the Swedish royal familyin honor of the Scandinavian country’s National Day.

A Washington Post special correspondent in Sanaa contributed to this report.