Syrian rebels pulled out of the key Aleppo district of Salaheddin yesterday in the face of a massive regime bombardment.
State television claimed the regime's special forces had "cleansed Salaheddin district of terrorists" but the rebel Free Syria Army said it would regroup and open new fronts in the battle for the country's commercial capital.
"We have staged a tactical withdrawal from Salaheddin. The district is completely empty of rebel fighters. Regime forces are now advancing into Salaheddin," said Hossam Abu Mohammed, an FSA commander.
"The fighters are withdrawing to Sukari district, where they are preparing a counter-attack," he said.
Mr Abu Mohammed said there had been heavy shelling and accused the regime of using thermobaric "fuel-air" bombs, which throw out a wall of fire to incinerate targets in enclosed spaces.
The Local Coordination Committees and the Syrian Observatory for Human Rights said yesterday's shelling was most focused on Salaheddin, as well as a northeast district and areas in the city's southwest.
An Aleppo activist, Mohammad Saeed, also said the government was using warplanes and tanks to shell the towns of Hreitan and Tel Rifat, about 40 kilometres north of the city.
"They are trying to cut the lines from Tel Rifat to Aleppo," he said.
Mr Abu Mohammed said about 40 rebels were killed in Aleppo yesterday. Nationwide, the death toll reached 78 - 35 civilians, 25 soldiers and 18 rebels - the Syrian Observatory for Human Rights said.
Amid the violence, the president, Bashar Al Assad, named the health minister Wael Nader Al Halqi, a Sunni member of the ruling Baath party from Deraa, as the new prime minister.
He replaces Riad Hijab, who defected this week to Jordan.
* Agence France Presse and the Associated Press