So .... who really blockades towns in Syria? Is it "dictator" Assad or the terrorist groups?

Truth or propaganda?  In wartime we gotta take everything with a grain of salt.  Some say Assad is using hunger tactics to tackle the terrorists by not letting food supplies get to the towns swollen with terrorists and thus innocent citizens are also starving along with the scum.  

And, then we have reports like the one below.  

From AlAlam:
.... Saudi-backed groups entered Nubbul and al-Zahra at the beginning of the insurgency in March 2011, but in July 2012 they completely blocked the area letting no food, medicine and supplies to enter. No one could leave the area or enter as well.
In May, a group of a thousand people tried to break the siege, but they were faced with terrorists who attacked the group brutally and killed and arrested many of them.
They beheaded 10 men and hung their heads at the entrance of the area so that no one else would run.
More than 50 thousand people live in these two towns while after the crisis broke out some 15000 people also migrated and set camp in there.
There are daily reports of abduction and killing of citizens in the area by terrorist groups who often film their crimes and post them on the internet.
It is estimated that at least 10 thousand terrorist are currently occupying the towns............