Five people were killed after a privately-owned helicopter carrying seven including four Russian passengers hit a television tower and crashed in Istanbul on Friday, state media reported.

Istanbul governor Vasip Sahin told state-run news agency Anadolu that five people were killed, as Turkish media speculated that foggy weather could be the cause.

There were two pilots and a Turkish passenger with the Russians on board the Sikorsky S-76 helicopter owned by Turkish conglomerate Eczacibasi, Dogan news agency said.