Ghouta airstrikes continue for fifth-straight day, despite repeated UN pleas for a ceasefire

Bombing raids continued on Friday morning, leaving at least another six civilians dead, according to the Syrian Observatory for Human Rights.

Then brief lull in bombing gave way to a mid-morning announcement over mosque minarets that warned of incoming strikes.

"From 2011 until now, there has never been the level of bombardment we've seen in the last 96 hours," said Hamza, a local doctor.

Eastern Ghouta is home to an estimated 400,000 people -the area is located on the outskirts of Damascus, and residents have been living under siege since 2013.

More than 4,000 families live in basements and bunkers, using them as shelter from airstrikes, according to Save the Children.

Intense airstrikes have made it difficult for aid workers to reach people in need.

"Our partners are having a hard time moving around, so how can they reach vulnerable people?" said Joelle Basoul, CARE International's Syria communications director.

Eastern Ghouta is meant to be part of the "de-escalation zones" declared last year as part of an international effort to reduce bloodshed in the nearly seven-year-old civil war.

But most experts say the Syrian regime appears intent to clear one of the last remaining rebel-held areas.

The UN has called repeatedly for ceasefires since the most recent bombing campaign began on Monday.