President Bashar al-Assad has named a new prime minister to replace Syria's most senior government defector while his forces pound rebels in a strategic district of Aleppo.
Mr Assad appointed Wael al-Halki, a Sunni Muslim from the southern province of Deraa, to head the government after Riyad Hijab fled on Monday after spending only two months in the job.
Mr Hijab's defection across the border to Jordan dealt another blow to Mr Assad's authority, already shaken by the assassination last month of four of his top security officials.
Mr Assad has focused his army counter-attack on Aleppo and Damascus, Syria's two main cities. He has reasserted control over much of Damascus.
Rebels fighting in the Aleppo district of Salaheddine, a southern gateway to the city, said they had been forced to fall back from some frontline positions today by a bombardment that had reduced buildings to rubble.
"There have been some withdrawals of Free Syrian Army fighters from Salaheddine," rebel commander Abu Ali said, adding that rebels were regrouping for a counter-attack.
Another combatant said at least 30 people had been killed in Salaheddine, where fighting has ebbed and flowed for two days.
Meanwhile, Iran has said an abrupt end to the rule of President Assad would have catastrophic consequences for Syria.
Iran is hosting a diplomatic meeting of its allies, which it says is the best way of resolving the intensifying conflict.
Russia has said it will attend the meeting at ambassadorial level but it was unclear what other key players would be present.
Iranian media has reported that China would attend along with at least 15 others, including Iraq, Pakistan, India and several members of the Arab League.
Elsewhere, veteran Algerian diplomat Lakhdar Brahimi is expected to be named to replace Kofi Annan as the United Nations Arab League joint special envoy for Syria.
A former Algerian foreign minister, Mr Brahimi, 78, has been a diplomatic troubleshooter for decades, having served as a UN special envoy for Iraq, Afghanistan, Haiti and South Africa.
