LONDON -- Israeli jets carried out airstrikes on a major air base in central Syria early today, according to Russia's defense ministry.
Two Israeli F-15 jets launched eight guided rockets from Lebanese airspace, targeting the T4 air base in Homs before Syrian air defenses shot down several of the rockets, Russia said.
Syrian state TV SANA reported that there had been casualties at the base, but Russia said no Russian military advisers were hurt in the attack. Five Iranian nationals were killed in the attack, the Iranian Tasnim News Agency reported.
The airstrikes come a day after a suspected chemical attack in Douma, a rebel-held area near Damascus, over the weekend.
Russian Foreign Minister Sergey Lavrov said there was no evidence of a chemical weapons attack, adding that Russian specialists and humanitarian workers had visited the area after rebel fighters evacuated following a deal with the Syrian government.
Both the United States and France had threatened a response over the suspected use of chemical weapons, with President Donald Trump and President Emmanuel Macron issuing a statement Sunday vowing to "coordinate a strong, joint response."
But both countries denied any involvement in today's airstrikes. The Israel Defense Forces has declined to comment.
"At this time, the Department of Defense is not conducting air strikes inside Syria. ... However we continue to closely watch the situation and support the ongoing diplomatic efforts to hold those who use chemical weapons, in Syria and otherwise, accountable," the Pentagon said in a statement.
On Saturday night, activists and doctors in the town of Douma said dozens of Syrians had been killed after a suspected gas attack near an opposition hospital.
Images and videos, which cannot be independently verified, showed dozens of bodies, including children and women, many with foam streaming from the nose and mouth.
Footage shot inside a hospital where people exposed to the attack showed children and men shaking and having apparent seizures.
Doctors at the hospital told journalists via WhatsApp that in addition to spasms and secretions from the mouth and nose, they had also treated patients with miosis, or constriction of the pupil, all of which are symptoms consistent with exposure to nerve agents.
More than 500 cases had been brought to doctors in local medical centers after the incident in Douma, the Syrian American Medical Society said.
On Sunday, Trump tweeted in response to the reports of the alleged chemical attack on Douma, saying Russia and Iran were responsible for backing "Animal Assad" and warning there would be a "big price to pay."
He also called for the area to be immediately open to humanitarian and medical assistance to treat the wounded.
In February, Israel confirmed it had carried out a raid over Syria, in a rare admission of action.
The airstrikes targeted Syrian air defenses and resulted in an Israeli jet's being downed during the mission, after an Iranian drone was launched into Israeli territory, according to Israeli Air Force Brig. Gen. Tomer Bar.
The pilots of the downed jet were able to parachute to safety before the craft crashed in northern Israel, Bar said.
The raid was "the most significant attack" since the 1982 Lebanon War, according to Bar.
Israel is said to have carried out around 200 airstrikes on Hezbollah and Syrian targets inside Syria since the start of the war, according to The New Yorker's Robin Wright. The vast majority aren't officially claimed by the Israeli military.
On April 4, 2017, a suspected chemical attack on Khan Sheikhoun, a rebel-held town in Idlib province, killed more than 100 Syrians and injured many more.
Two days later, Trump ordered an attack on the Syrian military base from which the chemical weapons were believed to have been launched. Fifty-nine Tomahawk missiles launched from U.S. Navy destroyers in the Mediterranean Sea targeted the Shayrat Air Base in Homs.
Speaking after the Khan Sheikhoun attack, Trump condemned the use of chemical weapons and blamed his predecessor, President Obama:
"These heinous actions by the Bashar al-Assad regime are a consequence of the past administration's weakness and irresolution. ... President Obama said in 2012 that he would establish a 'red line' against the use of chemical weapons and then did nothing."