Over 50 civilians were killed after Syrian President Bashar al-Assad’s regime forces conducted airstrikes on the rebel-held city of Douma, northeast of Damascus, on Saturday.
Dozens of bodies were recovered after a four multi-storey building were directly hit from above.
“There are entire families still under the rubble. We couldn't reach them yet, because as you know the process of removing debris must be done with extreme caution," a Syrian civil defense corps official was quoted by Reuters.
The latest airstrikes takes the death toll in Douma to over 150 people in a week. Around 100 people were killed when airstrikes by the regime targeted a busy market last Sunday.
A Syrian military source claimed the airstrikes targeted the headquarters of the prominent armed opposition group Islam Army, which is led by Zahran Alloush.
After the bombing, the UN Security Council unanimously approved a joint statement draft backing negotiations on ending the crisis in Syria.
The statement supports UN mediator in Syria Staffan de Mistura's plan to work towards "political negotiations and a political transition" based on the Geneva Communique which was adopted by world powers in June 2012.
The war in Syria started in 2011 in the form of anti-government demonstrations, but descended into a civil war between five main factions - the regime, the opposition, Al Qaeda-affiliated Nusra Front, ISIS, and the Kurdish People's Protection Units (YPG) militia.
As of June 30, at least 19,205 airstrikes were carried out by the regime’s air force, this year alone, the UK-based Syrian Observatory for Human Rights reported.
The regime’s helicopters have also dropped at least 10,433 barrel bombs on different areas in Syria, killing more than 2,916 civilians, including 456 women and 665 children, while 18,000 other civilians were wounded.
Over four years of fighting in Syria has left over 250,000 Syrians dead, according to UN estimates.
More than 6.7 million are displaced internally while at least 5.4 million have fled the country to neighbouring countries of Turkey, Lebanon, Egypt and Jordan.