The strikes hit several positions near Damascus and targeted a research centre and a military airport west of Syria's Homs city, the Syrian Observatory for Human Rights said.
Israeli air strikes in Syria left nine people – mostly foreign pro-regime fighters – and six civilians, including three children dead, a Britain-based war monitor said Monday.
The raids near Damascus and in Homs province late on Sunday killed the fighters, but it was not immediately clear exactly how the civilians died – whether in the strikes or in the aftermath, the Syrian Observatory for Human Rights (SOHR) said.
It said the strikes hit several Iranian positions near Damascus and targeted a research centre and a military airport west of the city of Homs – close to the border of Lebanon – where the Lebanese movement Hezbollah and Iranians are deployed.
One of the pro-regime fighters killed was Syrian, while the rest were of other nationalities, Observatory chief Rami Abdel Rahman said.
Regime news agency SANA earlier said four civilians had been killed after its air defences responded to an Israeli attack.
"Our air defences confronted enemy missiles launched by Israeli warplanes... towards some of our positions in Homs and in the vicinity of Damascus," SANA said, quoting a Syrian regime forces source.
An Israeli military spokeswoman declined to comment on the report.
Israel has carried out hundreds of air strikes in Syria since the beginning of the conflict in 2011, targeting forces loyal to regime leader Bashar al Assad and the regime's allies Iran and Hezbollah.
On June 12, Israeli warplanes struck a Syrian regime forces position in the country's south.
For years, Israel has remained largely silent about its attacks against Iran and its Shia proxies operating in neighbouring Syria. But in recent months, military and political leaders have become increasingly outspoken about these activities.