SANAA: Diplomatic efforts to end months of protests demanding President Ali Abdullah Saleh step down have made some headway, an opposition official said Sunday, with differences narrowed down to who controls the army during a transitional period.

Progress toward a deal came a day after hundreds of troops from the Republican Guard, an elite force led by Saleh’s son Ahmad, defected to join protesters camping out in central Sanaa since February to demand an end to the leader’s 33-year rule.

An opposition leader said talks with government representatives, mediated by U.N. envoy Jamal Benomar, moved closer to an agreement on a Gulf Arab plan to ease Saleh from power. It would transfer power to his deputy, Abd-Rabbu Mansour Hadi, before early an presidential election.

“There is progress in the negotiations,” the leader in a coalition of opposition parties told Reuters. He declined to be identified.

“The differences now focus on the president’s military authorities. The opposition wants these powers to be transferred to a committee that will be responsible for the armed forces until a new president is elected.”

Saleh would retain his title during the interim period but Hadi would take over his powers, the opposition figure said. Yemen’s opposition say Saleh wants overall control of the army, while they seek the power to sack commanders who disobey orders.

Saleh, who has three times backed away from signing the accord, told Republican Guard soldiers he visited Saturday that he was considering stepping down.

“We in the presidency of the state are willing to sacrifice for the nation, but you will stay, you are present ... you are the authority of power,” according to state news agency Saba.

Saleh’s ruling General People’s Congress party said Saturday an agreement to implement the Gulf initiative could be finalized within two days and signed in Riyadh. An opposition official subsequently dismissed prospects of an imminent deal.

Benomar, who arrived in Yemen last week to follow up on a U.N. Security Council resolution calling on Saleh to sign the Gulf initiative, has delayed plans to leave before a Nov. 21 deadline to report to the U.N. secretary-general.

Earlier Saturday, hundreds of Republican Guard troops defected, saying they would no longer agree to use force against protesters, activists said.

“We joined the revolution because we do not want to participate in the bloodshed and killings practiced by Saleh and his forces in [the southern city of Taiz], Sanaa and in Arhab [in northern Sanaa],” a member of the force told demonstrators.

In the southern port city of Al-Mukalla, a colonel in the army was shot dead by gunmen on a motorcycle, according to a local official.

It was the latest in a series of drive-by attacks on security or military officers in southern Yemen, which officials blame on militants believed to be linked to Al-Qaeda.

Militants have seized swathes of territory in southern Yemen in the chaos created by 10 months of unrest. In Arhab, an opposition website reported that a child was killed Sunday during shelling by government forces on the tribal area north of the Yemeni capital.