Rescuers, doctors in Syria's rebel-held Idlib says chemical gas used

"There were 16 killed, two of them children, in intensive air raids carried out by the regime against several regions of Eastern Ghouta", the Syrian Observatory for Human Rights said.

The onslaught came a day after a rash of airstrikes battered Syrian opposition areas, killing more than 28 people around the country and striking at hospitals and residential buildings in the northwestern Idlib province.

It was the second attack in a week on Turkish soldiers trying to establish a position near the front line between rebels and pro-Syrian government forces, under a deal with Russian Federation and Iran meant to reduce fighting in the area.

So far an estimated 134 Free Syrian Army fighters, 106 YPG fighters, and 68 civilians have been killed as a result from the current conflict between the SDF and Turkish military forces in northern Syria.

The UN mission in Syria warned of "dire consequences" to the compounded humanitarian crises besetting the country, and identified seven areas requiring urgent humanitarian relief.

The Russian Ambassador Vassily Nebenzia terming the U.S. statement as propaganda campaign against President Bashar al-Assad.

Mr Pinherio stressed that the ongoing fighting and deliberate obstruction by forces at front lines was blocking aid organisations from reaching civilians. The activist-run Ghouta Media Center said at least two, Douma and Harasta, were struck by ground-to-ground missiles.

Meanwhile, Turkish operations against Syrian Kurdish forces and USA and Russian-backed operations against ISIL continue to compound the suffering of Syrians in the country's north and east.

One Turkish soldier was killed and five were wounded on Monday in a rocket and mortar attack by militants as the Turkish forces were setting up a military post in Syria's Idlib province, Turkey's armed forces said on Tuesday.

In Idlib, Russia has intensified air raids on rebel-held towns after jihadist fighters shot down a Russian warplane and killed its pilot.

According to the Turkish General Staff, the operation aims to establish security and stability along Turkey's borders and the region as well as protect Syrians from terrorist oppression and cruelty.