At least 150 civilians requiring urgent medical treatment have been evacuated from opposition-held Eastern Ghouta, the current major battleground in Syria's seven-year war.

They were evacuated on Tuesday under a deal reached between Jaish al-Islam, one of the largest opposition groups in the area, and Russia - the Syrian government's principal ally.

According to the Syrian Observatory for Human Rights (SOHR) - a UK-based war monitor - the evacuees were taken to shelters under government control in other parts of the Damascus suburbs.

The area, which is a suburb of the capital, Damascus, where the government of President Bashar al-Assad sits, has been under siege by the latter's forces since mid-2013.

{articleGUID}

Eastern Ghouta, home to 400,000 people, has been under international spotlight in recent weeks due to the plight of civilians during an intensified government campaign to retake control from the armed opposition.

Since the start of the campaign on February 18, at least 1,196 civilians have been killed in daily aerial and ground bombardment by the Syrian government and Russia, according to the SOHR. The figure includes 245 children and 164 women. At least 4,600 others have been wounded.

The United Nations has said that at least 1,000 sick and wounded residents of Eastern Ghouta are in need of life-saving medical attention.

The evacuations come as the Syrian government makes major advances in Eastern Ghouta in one of the deadliest offensives against the opposition since the battle for Aleppo in 2016, when the rebels were dealt their worst defeat in the war.

Syrian government forces have captured more than half of Eastern Ghouta, splintering it as they seek to crush the last major rebel bastion.

Their advances have cut off the towns of Douma and Harasta from each other and from other neighbouring towns.

Fighter evacuations

Separately, at least 1,000 fighters and their families were evacuated from the district of Qadam, a neighbourhood in the southern part of Damascus, on Tuesday, according to the SOHR.

"The fighters and their family members numbered around 1,300. They were transferred to areas under opposition control such as Idlib, and Jarabulus," Rami Abdel Rahman told Al Jazeera.

According to Abdel Rahman, the fighters were mainly from the Hay'et Tahrir al-Sham (HTS) - a group formerly linked to al-Qaeda.

{articleGUID}

Fighters in Eastern Ghouta, however, have vowed to resist evacuation attempts and to continue their battle against the forces of President Assad, who they aim to topple.

The armed opposition groups in Eastern Ghouta, Jaish al-Islam and Faylaq al-Rahman, are linked to the Free Syrian Army - a loose conglomeration of armed brigades made up of Syrian army defectors and ordinary civilians, which receive financial and logistical support from the United States, Turkey, and several Gulf countries.