Photo released by Iranian media reportedly show the T-4 air base in central Syria after a missile barrage Monday.
Forces from regime allies Russian Federation and Iran, as well as fighters from the Tehran-backed Lebanese Hezbollah militia, are known to have a presence there, said Observatory chief Rami Abdel Rahman. A war-monitoring group said the airstrikes killed 14 people, including Iranians active in Syria.
Syria and Russian Federation on Monday accused Israel of bombing a Syrian regime airbase by using its warplanes.
If and when the Iranians decide to attack Israel, he added, they will not do so from their own territory.
Iran on Sunday condemned allegations of a chemical attack on Syrias Eastern Ghouta rebel holdout as a "conspiracy" against its ally President Bashar al-Assad and a pretext for military action.
The ministry said Syria will not hesitate to "practice its right to defend its land, people and sovereignty by all means that are in accordance with the United Nations charter".
Last week, President Vladimir Putin of Russian Federation met with his Iranian and Turkish counterparts to determine the future of Syria, a development Block warned "should send chills down our spine".
Earlier, President Donald Trump had promised a "big price to pay" for the suspected chemical attack.
The U.S. has consulted with allies to coordinate a joint response to Syria's alleged chemical weapons attack.
Eastern Ghouta, which is home to almost 400,000 people, fell to multiple militant groups in 2012, months after Syria plunged into crisis and has since served as a launch pad for fatal attacks against residents and infrastructure in Damascus.
"It seems the US government is looking for an excuse for military intervention", Iran's foreign minister, Mohammad Javad Zarif, said has he arrived in Brazil early on Tuesday, according to state media.
This assault comes after a chemical weapon attack on civilians in Damascus' rebel-held suburb of Duma.
"The Zionist regime and the USA have in different stages rushed to the scene to boost the morale of terrorists", he said, according to Iran's Press TV.