ISTANBUL (Reuters) - A blast was heard in the southeastern Turkish city of Gaziantep late on Friday but police were unable to find any signs of damage, the governor’s office said, adding the noise could have been caused by warplanes breaking the sound barrier.

State-run Anadolu news agency said police and fire fighting teams had been sent to the suspected area of the blast.

A statement from the provincial governor’s office, shared by Gaziantep Mayor Fatma Sahin on her Twitter account, said the security forces had investigated reports of the blast noise but found no signs of damage or casualties.

“It was assessed that the noise could have been caused by our planes taking part in the Euphrates Shield operation breaking the sound barrier,” the statement said.

Gaziantep province borders Syria where the Turkish military and Syrian rebels have for three months been conducting an operation to push Islamic State militants and a Kurdish militia away from the border.