Fighting raged in Syria's second city Aleppo on Monday amid a disputed claim that the army had managed to seize the strategic district of Midan from rebels, the Syrian Observatory for Human Rights said.
The army clashed with rebel fighters in several districts of the northern city, which has been the site of fierce fighting since July 20, the Observatory said.
One battle broke out near a building housing the feared air force intelligence service, and rebels also attacked a military post in the New Aleppo area.
Pro-regime Syrian newspaper Al-Watan claimed that the army had "cleansed" the Midan district, where the "majority of the armed men were Arab and foreign extremists."
But Observatory director Rami Abdel Rahman said the account was untrue.
"Clashes are ongoing in Midan and in several parts of Aleppo. Such claims are just part of the media war," he said.
Meanwhile, the Britain-based monitoring group said the army shelled the strongly pro-rebel district of Al-Hajar Al-Aswad in Damascus in preparation for storming it.
"The army started to shell ... over an hour ago," the Observatory said late morning, "and it is trying to storm the district."
"According to initial reports, one person has been killed there, and several have been injured."
The latest violence comes a day after at least 148 people were killed across Syria, most of them civilians, according to the Observatory.
In addition, some 28 unidentified corpses were found across the strife-torn country, including 16 people who had been summarily executed in the Qadam district of Damascus and 11 who had been shot dead in Kfar Sousa, also in the capital.
The watchdog has said that, as the war becomes increasingly brutal, it is becoming more difficult to document the death toll.