File photo: A general view shows a Syrian pro-government forces member walking past damaged buildings in the eastern city of Deir Ezzor on November 4, 2017.
"Four people were killed and eight wounded in a drone strike near a weapons factory band near a truck loaded with weapons," Rami Abdel Rahman of the Syrian Observatory for Human Rights told AFP.
The Observatory, which is based in the UK , could not immediately clarify who carried out the strike in the eastern city of Deir Ezzor.
It targeted a part of the city that controlled by Iran-backed factions and is home to residences of top Iranian commanders and senior officers of Lebanon's Hezbollah movement as well as an Iranian hospital to treat cholera patients, Abdel Rahman said.
Pro-Iran factions aligned with the Syrian government are heavily deployed south and west of the Euphrates River which runs through Deir Ezzor province.
A landmine exploded in the same neighbourhood, causing casualties, the official Syrian agency SANA reported.
"A number of citizens were killed and wounded when a landmine planted by terrorists exploded in the Al-Hamidiya neighbourhood of Deir Ezzor," SANA said.
Deir Ezzor is an important border crossings connecting Iraq to Syria .
In January, eleven people were killed in this region during a series of airstrikes.
Wednesday's attack followed a series of unclaimed drone strikes on January 30 that targeted a suspected convoy in the province and killed 11 people, including a pro-Iranian commander, the Observatory said at the time.
Israel has carried out hundreds of strikes on targets inside government-controlled parts of Syria in recent years, including attacks on the Damascus and Aleppo airports, but it rarely acknowledges or discusses the operations.
The latest, attributed to Israel by Syria, dated Tuesday, when warplanes struck Aleppo airport, in the north of the country, causing significant damage that halted flights to and from Syria's war- and quake-battered second city, the defence ministry said.
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