A coalition of Syrian opposition groups requested the suspension of U.S.-led airstrikes against the Islamic State terror group in Syria pending an investigation into reports that the campaign killed more than 50 civilians this week.
Syrian National Coalition president Anas al-Abdah warned in a letter to the foreign ministers of the anti-ISIS coalition that the killings of civilians by U.S.-led aircraft would "prove to be a recruitment tool for terrorist organizations."
The Britain-based Syrian Observatory for Human Rights reported that at least 56 civilians were killed in air strikes Tuesday north of the ISIS-held city of Manbij, including 11 children. The group said a day earlier that 21 civilians had been killed in the city.
Abdah called on the foreign ministers of countries fighting ISIS to halt air strikes while the reports are being investigated.
"It is essential that such an investigation not only result in revised rules of procedure for future operations, but also inform accountability for those responsible for such major violations," Abdah wrote.
U.S. Defense Secretary Ash Carter said Wednesday that the U.S.-led forces would assess the reports of civilian casualties in the region.
The Syrian foreign ministry blamed Tuesday’s air strike on French forces while he said Monday’s strikes were carried out by American jets.
"[Syria] condemns, with the strongest terms, the two bloody massacres perpetrated by the French and U.S. warplanes and those affiliated to the so-called international coalition which send their missiles and bombs to the civilians instead of directing them to the terrorist gangs," the ministry said in a letter sent to the United Nations this week.
French President Francois Hollande disputed that French planes were responsible, while a spokesman for the U.S.-led coalition said there were "multiple national aircraft" striking in Manbij, making it difficult for the Syrian government to detect who conducted specific strikes.
The U.S. Treasury Department on Thursday slapped sanctions on eight people and seven companies for supporting the Assad regime and assisting its weapons program.
The companies included a shipping business used by the Syrian Air Force and a firm that supplied aircraft tires to the Syrian defense ministry.