Syria's Eastern Ghouta, Under Siege since 2013

Syria's ruined rebel holdout region of Eastern Ghouta, from where urgent UN-demanded medical evacuations started on Wednesday, has been under siege for four years, suffering attacks and malnutrition.

Here is a summary of what has happened in the area, home to around 400,000 people:

- Battle for Damascus -Free Syrian Army (FSA) rebels launch an attack on the capital from its suburb of Ghouta in July 2012, more than a year after the start of an uprising against the regime.

After a week of fighting, the army asserts control of most of Damascus, but parts of its suburbs fall into rebel hands.

Fighting flares again at the end of 2012 as the rebels set up base in Eastern Ghouta.

The area becomes the target of regular bombings and artillery strikes; markets, schools and hospitals are hit. 

From 2013 Eastern Ghouta is totally under government seige.

- Sarin gas -In August 2013, hundreds of people including several children are killed in a chemical attack on Eastern Ghouta and another rebel bastion near Damascus, Moadamiyet al-Sham.

The opposition blames President Bashar al-Assad's regime, which denies involvement.

Washington also squarely accuses the Syrian government of responsibility, saying more than 1,400 people, including 426 children, were killed.

US and French retaliatory strikes are averted only after a September 14 US-Russia agreement that Syria's chemical weapons arsenal will be destroyed.

A UN report concludes days later that the use of sarin gas had been proved "unequivocally and objectively".

- Malnutrition -In November 2016, UN humanitarian operations chief Stephen O'Brien says nearly one million Syrians are under siege, including in Eastern Ghouta, in a "deliberate tactic of cruelty".

Following the release of shocking images of severely malnourished children in Eastern Ghouta, the United Nations in October 2017 condemns "the deliberate starvation of civilians as a method of warfare".

The following month, UNICEF says childhood malnutrition levels in the region are the highest recorded in Syria since the war began.

A survey in November showed that 11.9 percent of children under five were suffering from acute malnutrition, compared with 2.1 percent in a similar survey in January, it says.

Once an important producer of food, Ghouta has been ravaged, with buildings and roads in ruin and costs soaring. 

While some food is still grown locally, or smuggled in, humanitarian access to the region has been limited despite regular appeals from aid agencies.

The United Nations says in late November that 500 people, including children with complex medical issues, need urgent evacuation from Eastern Ghouta.

At least 16 people have died while waiting for evacuations to begin, UN humanitarian taskforce for Syria chief Jan Egeland says on December 21.

- 'De-escalation zone' bombed -Eastern Ghouta is in May 2017 identified as one of four "de-escalation" zones, but the government maintains its blockade and renews bombardment in mid-November.

The Syrian Observatory for Human Rights monitoring group says that 211 civilians, including 49 children, are killed in the bombings.