According to our correspondent, three mortar shells landed in the cities of al-Nubbul and al-Zahra early on Wednesday. There were no causalities.
Residents of the towns are facing severe life conditions including the epidemic infections after months of siege imposed by the militants.
All the roads to the cities are blocked by the terrorists and there is no way to send any emergency or medical aids to the residents.
Syria has been struggling with a US-backed insurgency which began in March 2011 as a protesting movement but turned to be a cover for terrorist groups including al-Qaeda and al-Nusra Front.
Fallowing Syrian army's successful operations in recent months, US government officials said that the White House was considering equipping the militants with more arms.