At least eight children have died at a refugee camp in southern Syria due to a lack of access to medical care and freezing temperatures.

Rukban camp, a sprawling mass of tents on the border with Jordan, has been largely cut off from essential food and supplies for a year amid a struggle for control over the strategic area between rival powers in Syria’s civil war.

The United Nations children’s agency said the “manmade” crisis that has blocked the camp’s 45,000 residents from receiving medical care has contributed to the death of at least eight children in the past month, most of them under four months old.

“Extreme cold and the lack of medical care, for mothers before and during birth and for new infants, have exacerbated already dire conditions for children and their families,” said Geert Cappelaere, Unicef regional director for the Middle East and North Africa.

“The lives of babies continue to be cut short by health conditions that are preventable or treatable. There are no excuses for this in the 21st century. This tragic manmade loss of life must end now,” he added.

Meanwhile, in eastern Syria, another seven children have died while fleeing fighting in the last Isis-held area of the country. The UN said families escaping heavy violence in the Hajin area of Deir Ez-Zor are forced to “wait in the cold for days without shelter or basic supplies”.

Rukban camp lies in an area ostensibly controlled by the US military, which operates a base nearby. But access on the ground is blocked by Jordan on one side and Syrian government forces on the other. Complicating things even further are a number of armed factions operating inside, which has made securing aid deliveries extremely difficult.

Jordan closed access to aid deliveries in 2016 following a deadly cross-border attack launched from the camp, and suspects Isis sleeper cells are still present there.

The camp’s residents – 80 percent of whom are women and children, according to the UN – had only been surviving on food smuggled in overground from other parts of Syria, but the Syrian army closed off those routes in October, making an already dire situation worse.

Lebanon storm hits Syrian refugee camps – in pictures Show all 15 1 /15 Lebanon storm hits Syrian refugee camps – in pictures Lebanon storm hits Syrian refugee camps – in pictures Khaled Alawi stands with his daughters in front of his home in an informal settlement for Syrian refugees in Akkar, northern Lebanon Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures A Syrian refugee child looks from his makeshift shelter at Qab Elias Syrian refugee camp in the Bekaa valley EPA Lebanon storm hits Syrian refugee camps – in pictures Children play in front of a shelter in Akkar Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures Syrian refugees Jose Ahmad al-Jessi, a mother of eight in her 50s, and her daughter Raghad, stand in the doorway of a shop warehouse, where they fled to when their tent flooded on Tuesday Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures Khaled Alawi surveys the damage to his shelter in Akkar Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures Syrian refugees sit inside their makeshift shelter in the Bekaa valley EPA Lebanon storm hits Syrian refugee camps – in pictures A young boy stands in front of his shelter in Akkar Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures A Syrian refugee child plays with snow outside their makeshift shelter in the Bekaa valley EPA Lebanon storm hits Syrian refugee camps – in pictures Richard Hall Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures A Syrian refugee shovels mud in front of a makeshift shelter follwoing rain storms in the Bekaa valley AFP/Getty Images Lebanon storm hits Syrian refugee camps – in pictures A shelter in Akkar Richard Hall/The Independent Lebanon storm hits Syrian refugee camps – in pictures Syrian refugee children play with snow outside their makeshift shelter in the Bekaa valley EPA Lebanon storm hits Syrian refugee camps – in pictures A Syrian refugee family pumps water after heavy rain in the Bekaa Valley AP Lebanon storm hits Syrian refugee camps – in pictures Syrian refugee children play outside their family tents after a heavy rain at a refugee camp in the town of Bar Elias, in Lebanon's Bekaa Valley AP Lebanon storm hits Syrian refugee camps – in pictures A flooded road leads to an informal settlement for Syrian refugees in Akkar Richard Hall/The Independent

In the past year, only two aid deliveries have made their way through to the camp, the last of which was in November.

As well as closing the border to aid deliveries, Jordan only allows the most serious medical cases to cross for treatment, which has caused preventable health issues to become critical.

More than a dozen people have died of malnutrition and lack of access to healthcare in a year. Among the victims were a five-day-old boy and a four-month-old girl who were unable to enter Jordan to reach a hospital, according to Unicef.

The difficulties faced at Rukban are being felt elsewhere, too. Devastating winter weather has made life unbearable for the millions of Syrians living in camps and tents inside and outside of the country. In northern Syria and across the border in Lebanon, rains have flooded camps and snow has blanketed tents.

An estimated 5.6 million Syrians have fled the country as refugees, and 6.2 million are displaced within Syria. Half of that number are children.

Unicef’s Mr Cappelaere said that more deaths are inevitable if nothing is done.

“Without reliable and accessible healthcare, protection and shelter, more children will die day in, day out in Rukban, Deir Ez-Zor and elsewhere in Syria. History will judge us for these entirely avoidable deaths,” he said.