U.S. official tells CNN an air strike close to Iraq-Syria border was carried out by Israel. IDF not commenting.

A United States official told CNN on Monday that an air strike on Sunday close to the Iraq-Syria border was carried out by Israel and not by the U.S. or the international coalition fighting the Islamic State (ISIS).

Syrian state TV blamed the strike that targeted pro-regime forces and caused multiple casualties on the U.S.-led coalition combating the terrorist group, but a spokesman for the coalition said there were no coalition strikes in the area, which took place al-Harra, southeast of Albu Kamal.

The IDF declined to comment on the strike, as per its normal policy.

U.S. officials have said that many pro-regime militias that are also aligned with Iran operate in the border area between Syria and Iraq.

The area is some distance from Israel and Israeli jets would have had to overcome significant logistical hurdles to strike that area.

Israel has in the past been accused of attacks in Syria. Last month, an air strike took place south of the capital, Damascus, and Syrian media said Israeli planes fired missiles at Iranian targets near Damascus.

In April, a military airbase belonging to the Assad regime near the Syrian city of Homs was hit with missiles. The Russian army, as well as Syrian media, claimed that two Israeli planes carried out the attack.

Prime Minister Binyamin Netanyahu has repeatedly warned about Iran’s presence in Syria. On Sunday, at the start of the weekly Cabinet meeting, he said, "We will take action - and are already taking action - against efforts to establish a militarily presence by Iran and its proxies in Syria both close to the border and deep inside Syria. We will act against these efforts anywhere in Syria.”

Netanyahu spoke with Secretary of State Mike Pompeo and Russian President Vladimir Putin over the weekend, two of the key players in influencing Israel's policy and actions over Syria.

CNN noted that Sunday's strike was very different from those normally attributed to Israel. Generally, those strikes occur in the western region of Syria, principally in the area around Damascus and Homs. Recently, these strikes have targeted Iran's infrastructure and military presence in Syria. Israel has also allegedly struck shipments of advanced weapons from Syria to Hezbollah in Lebanon in the past.

But this attack in Eastern Syria, the report continued, took place hundreds of miles away from that area, and the target -- pro-regime forces -- differs from what would be Israel's usual mark, namely Iranian military positions.

The Syrian army, alongside allied Iran-backed militias including Hezbollah and Iraqi groups, drove ISIS from Albu Kamal and its environs last year, but the jihadists have since staged attacks in the area.

In May, a military unit run by Hezbollah said warplanes from the U.S.-led international coalition targeted two Syrian army positions in eastern Syria.

In April, the United States, Britain, and France attacked eight pre-selected targets in Syria. The strikes came in response to Syrian President Bashar Al-Assad's use of chemical weapons against civilians in Douma.