June 18 (UPI) -- The United States military has denied responsibility for a series of airstrikes in Syria Monday that killed dozens of government forces.
The Syrian Observatory for Human Rights said at least 40 government fighters loyal to President Bashar al-Assad died in the attack overnight.
The death toll is expected to rise, the British-based watch group said.
Syrian state news agency SANA said the U.S.-led coalition launched the airstrikes that targeted military positions in the Deir Ezzor area.
SANA called the coalition strikes a "desperate attempt" to raise the morale of rebels groups and terror organizations.
If the U.S.-led coalition was responsible, the attack would mark the second major bombing of Syrian Army troops in the past year.
Pentagon spokesman Maj. Adrian Rankine-Galloway told Russia's TASS news agency the United States did not conduct the airstrikes.
"We haven't carried out a strike in Abu Kamal," Rankine-Galloway said.
U.S. Central Command spokesman Maj. Josh Jacques also said U.S. and coalition forces were not involved.