Syrian activists say at least eight people have been killed after government forces launched fresh attacks in several cities.
Six people were reported killed in Hama on Monday amid shelling by army tanks, with two more killed in Al-Bukamal and Deir ez-Zoor in the east.
Residents of Hama say the military resumed indiscriminate shelling and firing as residents were breaking their daily dawn-to-dusk fast on the first day of the Muslim fasting month of Ramadan.
The attacks appeared aimed at preventing mosque gatherings during special evening prayers, which security forces feared could trigger large anti-government protests.
The latest deaths bring the number of people killed since Sunday to at least 150.
A witness in Deir ez-Zor told Al Jazeera that government forces launched fresh attacks on the town early on Monday morning.
"Military forces stormed the city from the west side and 25 people are killed and more than 65 injured," the witness said.
"Artillery and anti-aircraft weapons are being used. The situation in the city is very bad, and medical and food supplies are low."
Deir ez-Zor, Syria's main gas and oil-production hub in the east, has become a rallying point for protests along with Hama.
Activist group Avaaz cited unconfirmed reports on Monday that the resort town of Zabadani near the Lebanese border was also under seige by the army.