Its deadly campaign to root out Islamist rebels controlling the area, already hit hard by a five-year government siege, has provoked an international outcry and demands for a truce.

Here is a timeline:

- Rockets, intense raids -

On February 18, government forces fire more than 260 rockets and the air force carries out intense raids on several areas in Eastern Ghouta.

The following day, regime forces again pound the region, killing 127 civilians in the highest death toll over a single day in the rebel enclave since 2013.

"The humanitarian situation of civilians in East Ghouta is spiralling out of control," says the UN's regional humanitarian coordinator for Syria, Panos Moumtzis.

- 'Hell on Earth' -

On February 20, Russian air strikes target Eastern Ghouta for the first time in three months, reportedly hitting the key regional Arbin hospital and putting it out of service.

Six other hospitals are also hit in the bombardments over a 48-hour period, putting three out of service, according to the United Nations.

Hundreds of injured flock to makeshift hospitals where the beds run short and patients are treated on the floor.

On February 21, raids target several areas and planes drop barrel bombs -- crude, improvised munitions that cause indiscriminate damage.

Several residential buildings are destroyed, according to an AFP correspondent.

The Kremlin denies involvement in the air strikes as "groundless accusations".

UN chief Antonio Guterres calls for an immediate ceasefire, saying the region's 400,000 residents "live in hell on Earth".

- 'Another Aleppo' -

On February 22, the chaos deepens as the Syrian regime rains rockets and bombs on the enclave, killing at least 19 people.

After weeks of talks at the United Nations on a truce, Russian ambassador Vassily Nebenzi says there is no progress.

Russia has been pressing for a negotiated withdrawal of rebel fighters and their families, like the one that saw the government retake full control of Aleppo in December 2016.

"Yes, Eastern Ghouta will become another Aleppo," says Syria's representative to the UN, Bashar al-Jaafari.

Doctors Without Borders says 13 of the facilities it supports in Eastern Ghouta were damaged or destroyed in three days.

- Ceasefire agreed -

On February 23, the Islamist rebel groups controlling Eastern Ghouta -- Jaish al-Islam and Faylaq al-Rahman -- reject any Aleppo-style evacuation plan.

US President Donald Trump slams the actions of the Syrian government and its Russian and Iranian backers.

"What those three countries have done to those people is a disgrace," he says.

On February 24, the UN Security Council unanimously backs a 30-day ceasefire to allow for humanitarian aid deliveries and medical evacuations.

The resolution is backed by Russia.

But there are new air strikes the following day and the Britain-based Syrian Observatory for Human Rights monitor reports that Syrian forces had engaged in heavy fighting with rebels, with many dead.

There are claims of the use of "chemical weapons, probably a chlorine gas attack", a doctor says, with a child dying and at least 13 other people suffering breathing difficulties.

Russia dismisses this as "bogus".

- Russia orders daily pause -

On February 26, the regime carries out fresh bombings, in spite of the UN-agreed truce, killing 22 civilians.

Frustrated, the UN and European Union demand the immediate implementation of the ceasefire.

Moscow later announces that President Vladimir Putin has ordered a daily five-hour "humanitarian pause" from February 27 and the opening of protected corridors to allow people to leave.