At least 23 members of Iranian and Syrian-regime forces were killed in Israeli air strikes in eastern Syria early Wednesday, and more than 28 militiamen wounded, some seriously, according to a U.K.-based war monitor.

The Syrian Arab News Agency (SANA) reported that Israel had struck targets in Deir ez-Zor Governorate, quoting a military source as saying that the strike occurred just after 1 a.m. but providing no further details.

The Syrian Observatory for Human Rights (SOHR) reported that the area between the city of Deir ez-Zor and the Syria-Iraq border, in the al-Mayadin and al-Bukamal districts, had been hit no fewer than 18 times. The targets included warehouses used to store weapons, according to the report.

Iranian Islamic Revolutionary Guard Corps (IRGC) forces, Lebanese Hezbollah and “Fatemiyoun”—aka Hezbollah Afghanistan—are known to be stationed in this region, which hosts a center for training fighters, according to SOHR.

AP quoted a senior U.S. intelligence official with knowledge of the attack as saying that the airstrikes were carried out with intelligence provided by the United States and targeted a series of warehouses in Syria that were being used as a part of the pipeline to store and stage Iranian weapons. The official said the warehouses also served as a pipeline for components that supports Iran’s nuclear program.

The war monitor reported on Tuesday that Fatimeyoun militia forces had unloaded a shipment of Iranian missiles that entered the country from Iraq into warehouses rented from civilians in the Kua Ibn Aswad area, between al-Mayadin city and the town of Mahkan in eastern Deir ez-Zor.

Wednesday’s airstrikes follow attacks on targets south of Damascus on Jan. 6 that Syrian state media also attributed to Israel. According to Step News Agency, an outlet identified with Syrian rebel groups, the target of the strikes was a facility, belonging to pro-Iranian militias, in Sahnaya village in the Syrian Golan Heights. SOHR reported several casualties in the strike.

On Jan. 7, SOHR reported that four people were killed and one wounded when an unidentified drone targeted a vehicle belonging to the Iraqi Popular Mobilization militia that had been attempting to enter Syria through an unofficial border crossing near the town of al-Bukamal.