One Syrian security official called it the "Starvation Until Submission Campaign", blocking food and medicine from entering and people from leaving besieged areas of Syria.
Forces loyal to President Bashar al-Assad have used partial sieges to root out rebel forces from residential areas during the civil war. But a recent tightening of blockades around areas near the capital is causing starvation and death, residents and medical staff say.
At an army checkpoint that separates government-held central Damascus from eastern suburban towns earlier this month, a thin, teenage boy on a bicycle circled a soldier and begged to be allowed to take a bag of pita bread, a staple food, into the eastern suburbs. The soldier refused but the boy kept begging for "just one loaf".
The soldier finally shouted: "I`m telling you, not a single morsel is allowed in there. I don`t make the rules. There are those bigger than me and you who make the rules and they`re watching us right now. So go back home." The soldier, visibly upset, exhaled quietly and deeply when the boy slipped out of sight.
The incident illustrates how blockades are being used as a weapon in a war that grew out of pro-democracy protests in the summer of 2011, increasing an already grave humanitarian crisis. Blockades are employed mostly by the government but also on a smaller scale by the armed opposition.
Food and medicine, which could be used by the warring parties, are rarely allowed to enter besieged areas and the movement of civilians in and out is restricted.
Over one million Syrians are trapped in areas where aid deliveries have stalled, the United Nations says.
The U.N. Office for the Coordination of Humanitarian Affairs said in a report last month that half of those people are in rural Damascus and around 310,000 people more trapped in Homs province in central Syria.
At a checkpoint in central Damascus, a state security official, known as Abu Haidar, was heard to say "we like to call it our Starvation Until Submission Campaign". It`s a phrase used increasingly by Assad`s supporters in the capital.
The Syrian government has not commented on accusations it is using hunger as a weapon of war. It says that residents have been taken "hostage by terrorists". Aid workers say they are denied access. Both sides use checkpoints to mark territory and prevent the movement of enemy fighters and supporters.
Rebel-held towns to the east, south and west of Damascus are under partial or total siege and Abu Haidar said that the army had begun to block off the towns of Qudsayya and Hameh, a 15 minute drive north from central Damascus onto the Qasioun mountain range.
Residents of these two towns said that earlier this month, on the first day of the Muslim holiday of Eid al-Adha, many were forbidden from leaving to visit family elsewhere.
Chances of success in getting past the checkpoints depend on your identity card - public sector workers and school children are sometimes allowed through. Parents are told to stay behind.
Some people were allowed to leave on foot and residents reported a small exodus of civilians who feared that artillery bombardment would follow the siege, as it has in other areas where rebels have positioned themselves.
The main checkpoint forbids most cars from entering or leaving the two towns, forcing people to get out of their vehicles, walk down the highway for 20 minutes and use public transport on the other side.
Soldiers conduct vehicle and body searches to prevent "smuggling" of bread, baby milk and medicine into the besieged area - jailing offences. The checks create long queues of residents trying to return home, sometimes forcing them to wait for hours.
All traffic is prevented from entering Hameh, a mostly Sunni Muslim town where many residents support the rebellion. There is some movement into Qudsayya, a more religiously mixed area that is home to tens of thousands of displaced Syrians from other parts of the country.
During a two-day visit by this journalist last month to the eastern towns, resourceful locals made do with what they had.
They gathered fruit and vegetables from the few orchards they could still access without risking government sniper fire and shelling. Those with cash paid smugglers to bring in bags of flour and other foodstuffs or medicine.
But nowhere in town was pita bread available. Local doctors said they regularly treat patients for water-borne diseases and that aerial bombardment has damaged the infrastructure, contaminating the water with sewage.
Doctors said that they were observing symptoms of malnutrition such as dehydration, severe weight loss, diarrhea and bloated stomachs.
International have little access to areas hit by violence. Groups like Save the Children are warning of a potential crisis. The agency released a report last month saying that parts of Homs, Aleppo, Idlib and Damascus have been encircled by violence or deliberately besieged.
In a separate development, the World Health Organisation confirmed an outbreak of polio among young children in northeast Syria on Tuesday - a consequence of falling vaccination rates in wartime.
The situation is acute for people living in Mouadamiya, on the southwestern outskirts of the capital Damascus, which has been under siege for a year and suffered from chemical weapons strikes and continuous bombardment.
Unlike East Ghouta, which also endured chemical attacks but is sometimes accessible, Mouadamiya is completely surrounded by the military.
The opposition says 12,000 people face starvation and death in Mouadamiya. About 90 percent of Mouadamiya has been destroyed and few doctors remain, it says.
This month, according to residents who live there reached by Skype, government aerial bombardment hit one of two remaining mains pipelines that deliver drinking water throughout Mouadamiya, further contaminating the local water supply.
Residents say that smugglers used to be able to throw bags packed with baby milk and medicine from moving cars into the town while driving along a nearby highway. But in July, the road became an active frontline between the army and rebels.
"No one can smuggle anything to us anymore," said resident and activist Qusai Zakarya. He said that many smugglers along the highway have been killed by government snipers. "Now, only shelling and bullets enter Mouadamiya, and only the souls of the departed can leave."
DYING OF HUNGER
For months, international pressure has been mounting on Syrian authorities to open humanitarian corridors to deliver aid to the besieged civilians.
Under international law, siege is not specifically prohibited. However deliberate starvation in a conflict is widely held to be a war crime and the law of armed conflict requires all sides to allow free access of humanitarian relief for civilians in need.
Although Syria is not party to the International Criminal Court - which can prosecute war crimes - the United Nations Security Council has the power to refer cases.
Three Security Council resolutions condemning Assad have been vetoed by permanent member Russia, one of his strongest allies, and China, making a referral unlikely.
Earlier this month, 3,000 women and children were evacuated from Mouadamiya, the United Nations said. But their suffering and starvation may continue as many have sought shelter in an abandoned school on the outskirts of Qudsayya, where the siege is starting.
On Tuesday, 1,800 residents were evacuated from the town, a source from the Ministry for Social Affairs said. State media said they were fired on by "terrorists."
Hunger has become so endemic that locals say they eat leaves and grass.
Fatima, who fled Mouadamiya just before the siege last year along with her husband and their five children to central Damascus, said one of her relatives died in Mouadamiya in August from starvation. He was three years old.
Local doctors sent Reuters videos showing six cases of death from malnutrition. Most of the victims were children.
Activist Zakarya said that this month alone, he knows of 11 women and children who died of starvation, including 7-year-old Dua al Sheikh, who was her parents` only daughter.
He said that after months of eating the rice, barley and bulgur wheat in stock, families are now down to little more than olives and olive oil for three meals a day.
"We sometimes roll a bunch of grape leaves together and sprinkle it with salt and pepper and eat it pretending it`s yabraa," said Zakarya, referring to a popular Syrian dish of grape leaves stuffed with rice and ground lamb or beef.
Civilians in besieged areas say farmers are targeted as they try to harvest their crop in an open field. They tell also of government shelling that purposely sets entire crop fields ablaze, around Damascus and in Homs province.
In Mouadamiya, people have been planting rocket plants in small patches of earth between buildings so as to avoid any open fields.
And Zakarya says "we use grass sometimes as a salad, with olives and olive oil."