In other areas of Syria, activists said that a further 33 people were killed.
The Syrian government news agency said that 17 people had been killed by anti-government gunmen. None of the figures could be independently verified.
The opposition Syrian National Council has urged the UN Security Council to act urgently after claiming that regime forces “massacred” scores of civilians, including many children, in the town of Houla.
At the same time, the Syrian Observatory for Human Rights accused the Arab and international communities on Saturday of being “complicit” in the killing, saying shelling that had begun on Friday had continued into the night.
The surge in violence came as Ban Ki-moon, the United Nations secretary general, told the UN security council there had been some progress in reducing violence, but the overall situation remained very serious.
“There is a continuing crisis on the ground, characterised by regular violence, deteriorating humanitarian conditions, human rights violations and continued political confrontation,” he reported to the security council in a letter.
‘Tanks in Aleppo’
Reports from activists and the government suggest that violence took places in dozens of areas involving helicopter gunships, tanks, artillery, roadside bombs and small arms.
On Friday, for the first time since the uprising against Assad’s regime erupted 14 months ago, army tanks rumbled through Aleppo, according to the Observatory.
It also said helicopter gunships went into action against rebels, strafing mountain villages in the Latakia area of northwestern Syria, near the Turkish border, wounding at least 20 people.
At least four policemen were killed in clashes with rebels in Kansebba, in the same area, the Observatory added.
Hours after massive anti-regime rallies across Aleppo, tanks deployed in the city, Syria’s economic hub, rumbling through the Kalasse and Bustan al-Kasr neighbourhoods after thousands attended a funeral, it said.