MISSILES have struck an air base in central Syria, its state-run news agency reported.

Though the agency claimed at first it was likely “an American aggression”, US officials said the US had not launched air strikes on Syria.

Russia’s defence ministry claimed that 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 then cited a source from its own military blaming Israel for the strikes.

The missile attack followed a suspected poison gas attack Saturday on the last foothold for the Syrian opposition in Douma in the eastern suburbs of Damascus.

At least 40 people were killed in the chemical attack, including families found in their homes and shelters, opposition activists and local rescuers said.

Russian Foreign Minister Sergei Lavrov claimed no evidence has been found of a chemical weapons attack on the formerly rebel-held town.

Lavrov said Russian specialists and aid workers had visited the area. Rebel fighters have started leaving the town under a surrender deal.

The Russian denial came hours after the attack on the air base, which Moscow and the Syrian government blamed on Israel.

The SANA news agency reported that the missile attack on the T4 military air base in Homs province resulted in a number of casualties. Fourteen people, including a number of Iranians, were thought to have been killed.

Russia’s defence ministry said the Israeli Air Force launched eight missiles on the base on the T4 air base in central Syria from Lebanon’s air space in the early hours of Monday.

The ministry said Syria shot down five out of the eight missiles that targeted the base. It said the other three landed in the western part of the T4 base.

Syrian state TV meanwhile quoted the unnamed military official as saying Israeli F-15 warplanes had fired several missiles while flying over neighbouring Lebanon.

Earlier, President Donald Trump had promised a “big price to pay” for the suspected chemical attack.

The US launched several dozen Tomahawk cruise missiles at a Syrian air base last year after a chemical attack in the northern Syrian town of Khan Sheikhoun killed dozens of people. Israel has also struck inside Syria in recent years.

The suspected poison gas attack Saturday on the besieged town of Douma came almost exactly a year after the US missile attack prompted by the Khan Sheikhoun deaths.

In response to the reports from Douma, Trump on Sunday blamed Syrian government forces for what he called a “mindless CHEMICAL attack.” In a series of tweets, Trump held Russia and Iran, Syrian President Bashar Assad’s chief sponsors, responsible.

The Syrian government denied the allegations, calling them fabrications.

First responders entering apartments in Douma late on Saturday said they found bodies collapsed on floors, some foaming at the mouth. The opposition’s Syrian Civil Defence rescue organisation said the victims appeared to have suffocated.

They did not identify the substance used, but the civil defense organization, also known as the White Helmets, and the Syrian American Medical Society, a medical relief organization, said survivors treated at clinics smelled strongly of chlorine.

Those reports could not be verified because of a government blockade around the town.

Hours after the attack, the Army of Islam rebel group agreed to surrender the town and evacuate their fighters to rebel-held northern Syria, Syrian state media reported. The group also agreed to give up its prisoners, a key demand of the government.

“There’s nothing left for civilians and fighters. We don’t have anything to stand fast,” said Haitham Bakkar, an opposition activist told reporters.

“People now are going out in the streets looking for their loved ones in the rubble,” Bakkar said. “And we don’t have any space left to bury them.”

More than 100 buses entered the town on Sunday night to transport fighters and their families to Jarablus, a town under the control of rebels and Turkey, said Syrian state TV.

Human rights groups and UN officials say the tactic amounts to forced displacement, a war crime. The UN Security Council planned to hold an emergency meeting Monday to discuss the attack.