Turkey vows Douma massacre perpetrators will pay 'heavy price'

Turkish President Recep Tayyip Erdogan on Tuesday vowed those behind the alleged gassing of civilians in the Syrian rebel enclave of Eastern Ghouta would pay a "heavy price" for the attack.

"I curse those who carried out this massacre. Whoever has done this, the perpetrators will be brought to account and certainly pay a heavy price," Erdogan told a meeting of his party in parliament.

The Turkish foreign ministry at the weekend said there was a "strong suspicion" that Syrian President Bashar al-Assad's regime was responsible for the attack.

But Erdogan on Tuesday steered clear of criticising Assad, only noting his telephone conversation with Russian President Vladimir Putin who is the chief ally of the Damascus regime along with Iran.

"I spoke with Putin yesterday (Monday), talks will continue today and tomorrow," he said. 

The Turkish leader on Monday expressed "concern" to Putin over the attacks in Eastern Ghouta, the Turkish presidency said.

Dozens of civilians were killed in a chlorine gas attack on Douma on Saturday, rescue workers and medics said - claims denied by Assad's regime and its ally Russia.

Ankara and Moscow have been on the two opposing sides of the war in Syria but despite their differences, both countries have worked closely in recent months for a political solution in Syria.

Both France and the US have pledged a forceful response against Syrian regime forces if found to be responsible for the Douma attack. President Donald Trump said "major decisions" would be made in the next two days, while France has vowed action if Assad crossed the chemical "red line".