The Center, which is affiliated with the Syrian opposition, claimed that 14 Syrian soldiers and 43 members of pro-Iranian militias were killed and 28 injured in the overnight attack attributed to Israel.
Israeli night raids targeting arms depots and military positions in eastern Syria killed at least 59 Syrian soldiers and allied fighters, in the deadliest raids since 2018, an activist group said on Wednesday. The Britain-based Syrian Observatory for Human Rights said 23 people were killed, including seven Syrians, and the rest were Iran-backed fighters.
Israel has been stepping up strikes against Iranian targets in Syria, part of aggressive posture adopted before President-elect Joe Biden takes office next week in what could bring a reassessment of Trump's "maximum pressure" policy on Iran.
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.
Israel hit around 50 targets in Syria in 2020, according to an annual report released in late December by the Israeli military.
"At 1.10am, the Israeli enemy carried out an aerial assault on the town of Deir Ezzor and the Albu Kamal region", Sana said, citing a military source.
A senior United States intelligence official told The Associated Press that the strikes targeted warehouses used to stage Iranian weapons in Syria.
The official said the warehouses also served as a pipeline for components that support Iran's nuclear program.
He described the air strikes as "a painful blow that indicates how much the Israelis are monitoring Iranian movements in every inch of Syria". In June 2018, 55 pro-government fighters were reportedly killed in the same region.
Israel is reported to have carried out three other rounds of air strikes in Syria in the past fortnight, hitting facilities, depots and positions in the southern and western outskirts of Damascus and in the Golan Heights.
The strikes came amid rising tensions in the region and amid concerns that Iran might carry out attacks to avenge last year's killing of one of its top commanders, Gen. Qassem Soleimani.