A total of 10 people were killed in a series of drone strikes targeting pro-Iran factions in eastern Syria, including three dead in strikes on Monday, a war monitor said.
A pro-Iranian commander was among the three killed in the drone strikes Monday, the Britain-based Syrian Observatory for Human Rights said, adding that they had been inspecting the site of strikes that had killed seven others the previous evening.
"A commander in an Iran-backed group and two of his companions, all of them non-Syrian, were killed this morning after renewed drone strikes," the Observatory said Monday.
The commander's pick-up truck was targeted while he was inspecting the site of the Sunday evening strike that destroyed a convoy of six refrigerated trucks transporting Iranian weapons to Syria from Iraq.
The convoy was struck in the Albu Kamal border region where pro-Iran groups have a large presence, said the Observatory, which has a wide network of sources inside Syria.
The seven killed Sunday were truck drivers and their assistants, all of them non-Syrians, the Observatory said, adding that they were "killed as a result of unidentified aircraft targeting a convoy of Iran-backed groups."
No country claimed the strikes, but Israel has carried out hundreds of air and missile strikes against Iran-backed and government forces in Syria, where the U.S. military is also active.
"The trucks were transporting Iranian weapons," Observatory chief Rami Abdel Rahman had told AFP Sunday.
Tehran provides military support to its ally Damascus in Syria's civil war, including through armed factions.
The strikes hit a convoy of trucks, but also the headquarters of Iran-backed groups in the area, activist Omar Abu Layla, who heads the Deir Ezzor 24 media outlet, told AFP Monday.
"There was heavy damage in the area that was struck," he said.
A pro-Syrian government radio station had reported Sunday that "unidentified war planes targeted, in a number of raids, six refrigerated trucks," without providing further details.
The Syrian government did not immediately comment on the strikes. AFP also reached out to Iraqi authorities who declined to comment on the attack.
The Observatory said at least two similar convoys had entered Syria from Iraq this week, offloading their cargo to pro-Iran groups in the eastern town of Al-Mayadeen.
Pro-Iran factions, including Lebanon's powerful Hezbollah group, have a major presence around the Iraq-Syria border, and are heavily deployed south and west of the Euphrates in Syria's Deir Ezzor province.
Both Albu Kamal and Al-Mayadeen are in Deir Ezzor, and Albu Kamal has seen similar strikes in the past.
The Observatory said in November that a strike in the area hit a pro-Iran militia convoy of "fuel tankers and trucks loaded with weapons," killing at least 14, though an Iraqi border guard official said there were no casualties.
In December, Israel's then-military chief Aviv Kohavi said his country had launched the raid, adding that the convoy was carrying weapons bound for Lebanon, where Hezbollah has an influential role.
Israel rarely comments on individual raids but has acknowledged carrying out hundreds of air and missile strikes in Syria since civil war broke out in 2011.
A U.S.-led coalition fighting the remnants of the Islamic State group in Iraq and Syria has also carried out strikes on pro-Iran fighters in Syria in the past.
The conflict in Syria started with the brutal repression of peaceful protests and escalated to pull in foreign powers and global jihadists.
Nearly half a million people have been killed in Syria's conflict, which has also displaced about half of the country's pre-war population.