Israel struck targets near the Quneitra province, Syrian media outlets reported Tuesday.
The Israeli army has yet to comment on the incident. Syrian state media also reported blasts heard near the Quneitra province in south-western Syria, near the border with Israel.
Videos posted on social media showing a missile or rocket exploding in the air were said to be taken from the Israeli side of the border, in the Golan Heights.
The Britain-based Syrian Observatory for Human Rights, an opposition war monitor, said the missiles struck areas where Iran-backed fighters are based.
In July, Syria accused Israel of conducting airstrikes twice within one week, including one on a weapons depot belonging to an Iran-backed militia outside Aleppo that killed five people employed by Iran's Revolutionary Guards.
In June, the Syrian Observatory for Human Rights said eight people had been killed in an alleged Israeli missile strike over Damascus.
Israel has launched hundreds of strikes against Iran-linked military targets in war-ravaged Syria over the years but rarely acknowledges or discusses such operations.
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Israel views Iranian entrenchment on its northern frontier as a red line, and it has repeatedly struck Iran-linked facilities and weapons convoys destined for Lebanon’s militant Hezbollah group.
Western intelligence sources say Israeli strikes on Syria are part of a shadow war approved by the United States and part of a policy to undermine Iran's military power without triggering a major increase in hostilities.
Thousands of Iranian-backed militias have had a growing presence across Syria in the last year after helping Syrian President Bashar Assad regain territory once lost to insurgents.
The Associated Press and Reuters contributed to this report.