Russia's Defence Ministry said two Israeli aircraft targeted the T4 air base in Homs province, firing eight missiles.
Israeli officials did not immediately comment on the reports.
The United States denied attacking the Syrian base. Israel reportedly has carried out dozens of airstrikes on Syria's army and its allies since 2011.
President Trump vowed there would be a "big price to pay" for the chemical attack but after the latest airstrike, Pentagon spokesman Christopher Sherwood said "at this time, the Department of Defense is not conducting airstrikes in Syria". Washington and Paris denied any involvement, and Damascus later blamed Israel.
Iran is a staunch ally of the Syrian government, and has deployed forces and assets inside Syria, including a network of pro-government fighters it uses as shock troops in battles with Syrian rebels.
It has also repeatedly warned it will not accept its arch-foe Iran entrenching itself militarily in neighbouring Syria.
In February, the Israeli Air Force downed an Iranian drone that came from the Tiyas base in airspace over northern Israel, and followed the infiltration by attacking 12 targets in Syria, including three aerial defense batteries and four Iranian targets that are part of Iran's military establishment in Syria. In a statement, it said a fact-finding mission was gathering information from all available sources to establish whether chemical weapons were used.
3rd death reported in IL linked to fake weed
Brodifacoum is a long-acting anticoagulant that affects levels of vitamin K in the blood which is necessary for clotting. IL alone has reported 107 cases, and three people have died, the state's Department of Public Health said Monday.
"The timing of the strike isn't coincidental", said Michael Horowitz, a senior analyst at Le Beck International, a Middle East-based geopolitical and security consultancy. Lindsey Graham (R-S.C.) said Syrian President Bashar Assad is a "legitimate war criminal" and the world is watching to see how President Trump responds. "Israel mitigates the risk of an Iranian response", he said.
As global officials worked to try to confirm the chemical attack, Trump took the rare step of directly criticizing Russian President Vladimir Putin in connection with the incident. The militants from Jaish al-Islam had been negotiating their exit with Russian representatives. Gen. Yuri Yevtushenko was quoted by Russian news agencies Sunday as saying Russia was prepared to send specialists to Douma to "confirm the fabricated nature" of the reports.
Nader said that the chemical attack on Douma opened the door for all worldwide players, particularly Israel, to widely intervene in Syria.
Over 10 people were killed in the pre-dawn attack on the T-4 airbase near Homs.
Footage from the area showed bodies strewn across the floor of an air raid shelter.
More than 500 people, mostly women and children, were brought to medical centres complaining of difficulties breathing, foaming at the mouth and burning sensations in the eyes. "Security in the present is a necessary condition for future security".
On Monday, Iranian Foreign Ministry spokesperson Bahram Qassemi condemned the attack, which he called a "violation of Syria's sovereignty and territorial integrity" by Israel. A year ago, almost 100 people were killed in a strike on the northern town of Khan Sheikhoun that the United Nations has blamed on the Syrian air force. Eglash reported from Jerusalem.