"We are forwarding the report to our Civilian Casualty Cell for further assessment on this allegation", the spokesperson for the coalition US Col. Sean Ryan told Rudaw English.
While local partner forces on the ground have pushed Isil out of most of Syria, its fighters still control a strip of mostly desert land along the Syria-Iraq border.
On April 19, the Iraqi Air Force conducted strikes against Islamic State forces near the Syrian-Iraqi border, in coordination with the Syrian government in Damascus.
The coalition was not immediately available for comment. The U.S. -led coalition does not directly coordinate with Assad, though it maintains a deconfliction line with his Russian ally.
Iraqi warplanes have recently carried out strikes in eastern Syria, while coalition aircraft have been supporting the PKK terror group's Syrian wing, the People's Protection Units (YPG). Since Moscow's intervention in Syria in 2015, however, Iraq has also maintained a joint operations room with Iran, Russia and Syria.
The Observatory later said that at least 54 people were killed or injured, and the strikes may have come from Iraqi or coalition forces.
The US-led coalition is fighting to crush the remnants of Islamic State on both sides of the border between Syria and Iraq.
According to Syrian state media, the number of the dead is expected to rise as scores remain trapped under the rubble and are in critical condition. In its latest offensive, the Syrian government has managed to mostly secure the country's restive southwest in a lightning offensive that saw the Syrian flag raised Thursday in Daraa, which was one of the last rebel-held cities in the country.
ISI was largely defeated in most of the territory it controlled in both countries past year, but fighters still operate in the desert near the border.