At least 52 foreign fighters allied to the forces of Syrian President Bashar al-Assad were killed in overnight airstrikes near the country’s eastern border with Iraq, AFP reported on Monday.

The Syrian Observatory for Human Rights, a Britain-based monitor of the conflict, claimed that the strikes targeted the village of Al-Hari – southeast of the town of Al-Bukamal – just before midnight. “Among them are at least 30 Iraqi fighters and 16 Syrians, including soldiers and members of loyalist militias,” said the monitor’s chief Rami Abdel Rahman. The nationalities of the remaining six fighters were not immediately known, he added.

While the observatory could not identify who carried out the airstrikes, the Syrian state media accused the United States-led coalition against the Islamic State group of bombing the regime’s positions, Reuters reported. However, Major Josh Jacques, the spokesperson for the US Central Command, refuted the accusation.

In February, the US killed 100 Syrian soldiers loyal to Assad in airstrikes in the province of Deir ez-Zor after the troops allegedly started a coordinated assault on Syrian opposition forces.