ANKARA (Reuters) - Gunshots were heard in the Turkish capital of Ankara on Friday, a Reuters witness said, as military jets and helicopters were seen flying overhead.

Reuters witnesses in Istanbul, Turkey’s biggest city, also spotted helicopters overhead.

Broadcaster NTV reported that both of Istanbul’s bridges across the Bosphorus, the strait separating the European and Asian sides of the city, had been closed to traffic.

It was not immediately clear if the events were related.