Russia blames Israel for strikes on Syrian airbase

Syria and it most powerful ally, Russia, blamed Israel for striking an airbase in the war-torn country on Monday, following a suspected chemical gas attack that drew condemnation from world powers.

Russia's Defense Ministry claimed two Israeli F-15 warplanes launched airstrikes on the T-4 base in central Syria from Lebanese territory, the state-run RIA Novosti news agency reported.

Syrian state media said that a number of people were killed or injured in the strikes and cited a military source blaming Israel for the military action.

Israel and Russia have coordinated their military actions over Syria for deconfliction since Russian forces entered the country in late 2015. The T-4 base, located in a strategic position between the cities of Homs and Palmyra in Syria's west, has been a key staging ground for Syrian and Russian aircraft during the war.

Syria claimed that its air defenses had shot down eight missiles fired at the airbase Monday, in strikes that killed and injured a number of people, while RIA Novosti reported three missiles flew to their target and a remaining five were shot down.

The country had earlier speculated that the US was behind Monday's strikes, which the Pentagon swiftly denied.

Trump: 'Big price to pay' in Syria

Syrian activist groups said toxic gas inside barrel bombs were dropped from helicopters over the rebel-held city of Douma on Saturday, killing dozens of civilians and wounded scores more.

Graphic footage shot by rescuers and activists show victims -- including children -- dead and injured, some ghostly white and foaming at the mouth in makeshift clinics. Others were found suffocated in their homes, according to first responders.

CNN could not independently verify the authenticity of the images.

Video shows Syrians affected by chemical attack 02:46

The Organization for the Prevention of Chemical Weapons said Monday that a fact-finding mission was working to establish whether chemical weapons were used.

US President Donald Trump on Sunday warned Russia, Iran and Syria of a "big price to pay" following the attack, and slammed Syrian President Bashar al-Assad as an "animal" on Twitter.

Trump blames Putin, Obama for 'Animal Assad.'

The Syrian government and Russia vehemently denied involvement and accused rebels in Douma of fabricating the chemical attack claims in order to hinder the army's advances and provoke international military intervention.

The attack came as Syrian forces were on the verge of reclaming Douma, the last town held by rebels in Eastern Ghouta, which was besieged for six years and has been heavily bombarded since mid-February.

On Sunday, Syrian state TV reported that the government had reached an agreement with Jaish al-Islam, the only remaining rebel group in the town, to leave in the next 48 hours.

As part of the agreement, the group's fighters would be transported to Jarablus in northern Syria. In exchange, the rebels would release all captives they are holding in Douma.

Tamara Qiblawi reported from Damascus. Mary Ilyushina reported and Angela Dewan wrote from London. James Griffiths contribued to this report.