Israel is behind an attack in Syria that killed dozens, CNN reported Monday, citing a U.S. official.

According to Syrian state television, the strike targeted pro-regime forces and caused multiple casualties. The airstrike took place on the Iraq-Syria border on Sunday and killed 22 members of a Shi'ite militia. The Syrian Observatory for Human Rights, a UK-based war monitor, said the number of pro-regime casualties had risen to 52.

The attack took place in al-Harra, southeast of the town of al-Bukamal, state news agency SANA said, citing a military source.

Open gallery view Israeli Defense Minister Avigdor Feldman with Prime Minister Benjamin Netanyahu in Israel's Knesset, October 23, 2017. Credit: Olivier Fitoussi

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Earlier today, Syrian state TV reported that the U.S.-led coalition struck a military position in the country's east. The Syrian Observatory for Human Rights reports that 40 pro-Assad regime fighters were killed in the strike.

The strike took place in al-Harra, southeast of al-Bukamal, Syrian state media said, though official reports did not confirm the death toll.

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According to CNN, Sunday's strike is unlike those normally carried out by Israel, as those attributed to Israel tend to occur in Syria's western region, around Damascus and Homs, and mostly targeting Iran's infrastructure and military presence in Syria.

Sunday's attack took place in Syria's east and targeted pro-Assad forces, not Iranian ones.

A commander in the military alliance backing Syrian President Bashar Assad also told Reuters that drones, “probably American,” had bombed positions of Iraqi factions between al-Bukamal and Tanf and Syrian military positions.

“No member of the U.S.-led coalition carried out strikes near Albu Kamal,” Major Josh Jacques, a U.S. Central Command spokesman, told Reuters.

The U.S.-led coalition is supporting an alliance of Syrian Arab and Kurdish militia fighting Islamic State northeast of al-Bukamal.