At least four people have been reported killed in a drone strike in Deir ez Zor, eastern Syria.
Eight others were wounded in the strike on Wednesday, which targeted a weapons factory belonging to Iran-backed groups, the Syrian Observatory for Human Rights told AFP.
A weapons-filled truck was also hit in the strike, it said.
It comes a day after flights carrying earthquake aid to quake-hit northern Syria were rerouted following a strike on Aleppo airport.
The Syrian government said Israel was behind the attack, which caused material damage, according to state news outlet Sana.
While Israel rarely acknowledges the strikes it carries out on regime-controlled territory, it has admitted to targeting Iran-backed proxies in Syria.
In December, former army chief Aviv Kochavi admitted Israel was behind a drone attack on a weapons convoy travelling from Iraq to Syria through areas controlled by Iran-backed proxies.
He said Israel's actions have "totally disrupted" Iran's aims to entrench itself militarily near Israel's borders, including preventing "hundreds" of missiles being placed in neighbouring Syria and Lebanon.
Five people were killed in suspected Israeli air strikes on Damascus in February.
