At least 30 civilians have been killed by Syrian government air strikes targeting Idlib province and Damascus suburbs, Al Jazeera's correspondent in Syria and a monitoring group said.
The UK-based Syrian Observatory for Human Rights said at least 19 people, including four children, were killed in raids hitting several neighbourhoods in Idlib province. Ten others were injured in the attack.
Al Jazeera's correspondent in the province said barrel bombs and tens of air strikes had targeted the Jabal al-Zawiyah area.
In the Damascus suburb of Douma, air strikes killed at least 11 people, including women and children, medical sources told Al Jazeera. Witnesses said massive destruction was caused.
Douma has been under government attack for 13 days in a row, with a death toll rising to over 150 civilians.
Al Jazeera's Samara Kouatly, reporting from Douma, said aid workers have spent days trying to recover bodies from under the rubble.
She added that Douma is running out of medical and aid supplies following recent air strikes as hundreds of those injured are in desperate need.
The UK-based Syrian Observatory said nine people, including six children, were also killed in the Damascus suburb of Arbeen.
Rockets hit central Damascus
As rebels fired back, at least 40 rockets fell in the capital Damascus on Monday, the Syrian Observatory said. One person was killed and 20 others were injured in the attacks.
Areas hit in central Damascus included Malki, where President Bashar al-Assad's home is located, as well as Abou Roumaneh, Baramkeh, Baghdad Street and Mazraa.
On Sunday, at least 30 people, including six children, were injured when 50 rockets hit central Damascus, the Syrian Observatory said.
The UN has said that about 250,000 people have been killed in Syria since 2011 and an estimated 7.6 million are internally displaced. Four million people have fled the country.
At least 6,673 air strikes were recorded during the month of July, including 3,654 barrel bombs dropped by government helicopters on 13 out of 14 Syrian provinces, the Syrian Observatory said in a report.
Damascus suburbs and Idlib province were the most targeted provinces, according to the group, which has a network of activists on the ground.
At least 791 civilians were killed in these air strikes, including 207 children below the age of 18. At least 3,000 others were injured while thousands were forced to flee their homes.
Source: Al Jazeera