Syrian activists say hundreds of people have been killed in airstrikes targeting rebel-held areas over the past few days.
The Syrian government forces continues to use barrel bombs - explosives packed inside drums and thrown from helicopters - which have been condemned as indiscriminate weapons.
The government has also deployed more troops to recapture the strategic Qalamoun area.
Al Jazeera's Hashem Ahelbarra reports.
Source: Al Jazeera