President Bashar al-Assad's regime has upped its rhetoric on retaking control of Idlib and surrounding areas over the past month.
It was the heaviest bombardment since August 10, when at least 53 civilians were killed in Idlib and the neighbouring province of Aleppo, he said.
The Journal reports almost two dozen civilians have died in the most recent attacks.
The Observatory said Saturday that some 2,000 people were already on the move from areas being bombed, heading deeper into Idlib province.
The Wall Street Journal has just published a bombshell on Sunday evening as Russian and Syrian warplanes continue bombing raids over al-Qaeda held Idlib, citing unnamed USA officials who claim "President Bashar al-Assad of Syria has approved the use of chlorine gas in an offensive against the country's last major rebel stronghold".
In response, President Donald Trump is considering military intervention which could involve targeting Russian or Iranian forces supporting Assad, the Wall Street Journal (WSJ) reports.
Mr Erdogan called for a "truce" at a press conference after the talks.
Lowcock acknowledged that "there is a large number of fighters there, including terrorists from proscribed organisations".
"When we speak to Syrians who have already been displaced three, five, even six times, they themselves say there is nowhere to go".
"Russia is reminding Turkey it needs to stay in Russia's good graces if Turkey wants to avoid a painful catastrophe in north-west Syria", Mr Heras told Agence France-Presse.
In the neighbouring province of Hama, Russian jets carried out more than ten strikes on rebel positions in the village of Al-Latamneh, he said.
"Perhaps Putin has come to the conclusion that the gap between Turkey and the West has reached an unbridgeable distance, and that he can disregard Ankara's wishes regarding Idlib because he sees that Turkey has nowhere to go in addition to being ever-more dependent on Russian Federation and Iran for energy", he said. Turkey is a leading opposition supporter which has troops in the country and has erected 12 observation posts around Idlib.
"There might be another refugee flow but we plan not to open our borders and settle the refugees in the camps prepared for them on the Syrian side of the border", Volkan Bozkir, the head of the Turkish parliament's foreign affairs committee and a former government minister, told the Cumhuriyet newspaper. "The consequences of inaction are vast", Erdogan said. The majority of the displaced have headed close to the border with Turkey.
Ground troops from the Syrian Democratic Forces (SDF), a Kurdish-led force, began moving against Isil remnants in the province of Deir Ezzor, the coalition said. Occasional clashes erupt there over turf control and authority, reflecting deepening political tension between the uneasy partners. The Asayish said seven of its members and 11 government personnel were killed. Many fear conscription or arrest. This prompted the clashes that lasted no more than 20 minutes, Sheikmos said.
There was no immediate comment on the clashes by the government.
"We're deeply concerned about this recent escalation of violence, which has resulted in the displacement of over 30,000 in the area".