Heavy Syria bombing wreaks havoc on Aleppo despite 'de-escalation zone'

At least 50 civilians, including 20 children, were killed on Monday in airstrikes on Syria's northern Aleppo province despite a "de-escalation zone" in place there, a monitor said.

The UK-based Syrian Observatory for Human Rights said three airstrikes hit the opposition-held town of Atareb, adding that the death toll was expected to rise as dozens of people were injured or still missing after the attack.

Activists said the strike was a "double tap" bombing, aimed at killing victims and emergency workers.

It was not immediately clear whether the deadly strikes were carried out by Syrian regime planes or those of Damascus' staunch ally Russia.

Graphic footage purporting to show the aftermath of the airstrikes has appeared online.

Atareb, in the west of the Aleppo province, is located in an area that part of a "de-escalation zone" agreed under a deal earlier this year between Russia, Iran and Turkey.

The zone covers most of the Idlib province which is largely held by opposition forces and an extremist group formerly affiliated with al-Qaeda.

Three zones are already in place across Syria in Eastern Ghouta near Damascus, in central Homs, and in parts of southern Syria, which are being monitored by Russian military police.

The fourth de-escalation zone includes Idlib but also parts of the neighboring Latakia, Hama and Aleppo regions.

In late September, Russian and Syrian regime airstrikes killed more than 150 civilians and injured dozens more in over a week of heavy bombings in the opposition-held Idlib province.

September was the deadliest month for Syrians this year, with at least 3,000 people killed following intense bombardments of Idlib and Islamic State group-occupied territories.

The Syrian conflict began when the Baath regime - in power since 1963 and led by Assad - responded with military force to peaceful protests demanding democratic reforms during the Arab Spring wave of uprisings.