Warplanes from the U.S.-led coalition targeted two Syrian army positions in the eastern Syrian desert, a military media unit run by Lebanon’s Hezbollah group said early on Thursday, but U.S. military officials denied any knowledge of the strikes.

The unit, a Damascus ally, said the strikes took place near T2, an energy installation located near the border with Iraq and about 100 km (60 miles) west of the Euphrates river where the coalition is backing ground forces against Islamic State.

A U.S. military official denied any knowledge of the strikes.

“We have no operational reporting of a U.S.-led coalition strike against pro-Syrian regime targets or forces,” Captain Bill Urban, a spokesman for U.S. Central Command, told Reuters.

Another Pentagon spokesman, who spoke on condition of anonymity, said: “We have no information to substantiate those reports.”

Syrian state media did not immediately report the strikes.

Eastern Syria was mostly held by Islamic State until last year, when two rival campaigns, one by the Syrian army backed by Russia, Iran and Hezbollah, the other by Kurdish and Arab militias backed by the U.S. coalition, took most of its land.

Communication between Russia and the United States averted most clashes between them. However, the coalition has struck Syrian pro-government forces that it said were attempting to attack coalition positions.

The U.S. military operating outside the coalition also maintains a base at Tanf in the eastern Syrian desert near the borders with Iraq and Jordan and last year struck pro-government forces moving along a road towards it.