At least 80 people were reported killed across Syria today, 52 of them civilians, as regime forces pressed a protest crackdown three days ahead of a deadline to cease fire and pull back.

Monitors reported the latest deaths despite UN chief Ban Ki-moon's latest rebuke to Damascus for stepping up its assault on dissent hubs ahead of Tuesday's deadline.

Forty civilians died "in bombardment and shooting on the town of Latamna," said the Syrian Observatory for Human Rights.

The Britain-based monitoring group said other civilians were killed in Tibet al-Imam, also in Hama, as well as in the neighbouring province of Homs, in Idlib to the northwest and Aleppo in northern Syria.

Sixteen rebels and 12 regime fighters were also killed nationwide, it said.

It said the deaths came after President Bashar al-Assad's forces launched an overnight assault on Latamna and clashed with members of the rebel Free Syrian Army.

UN-Arab League envoy Kofi Annan has warned of "alarming" casualties as the Syrian government's year-long crackdown on dissent -- which the United Nations says has killed more than 9,000 people -- showed no signs of abating.

Monitors put the number of dead at more than 10,000.

At least 77 people were killed nationwide on Thursday and 35 on Friday, mostly civilians, according to Observatory figures.

Today, rebels attacked a military intelligence headquarters in the second city of Aleppo, the Observatory said, and army deserters also pressed a dawn assault on Ming air base in the same province.

Fighting was also reported between troops and deserters in districts of Hama city.