ISTANBUL 芒鈧珺次元官网网址� A helicopter crashed on a highway in the outskirts of Istanbul on Friday after apparently hitting a television tower in dense fog, reports said. At least five people were killed, the governor said.

The Sikorsky S-76, belonging to the Eczacibasi group of companies, was carrying seven people 芒鈧珺次元官网网址� the company's four Russian guests, a Turkish official and two pilots.

Gov. Vasip Sahin said the helicopter crashed in Istanbul's Buyukcekmece district after taking off from Ataturk Airport, adding that the cause of the crash is under investigation. There was no immediate information on the fate of the two others reported to be on board.

Thick black smoke could be seen billowing from the crash site in video shown on Turkish network DHA. Burning debris was scattered across a large stretch of the highway.

B次元官网网址 from a helicopter showed rows of rescue vehicles at the crash site and traffic piling up as vehicles were diverted off the highway to other roads.

Eyewitness Fikret Karatekin, a taxi driver, told CNN-Turk television by telephone that the helicopter slammed into the tower before crashing on the highway.

"It hit the tower and crashed by spinning," he said.

Authorities however, did not rule out a technical fault as the cause of the crash.

The tower, which is no longer used for transmitting television signals but has a restaurant at the top, did not appear to be damaged.

Bulent Eczacibasi, who heads the company 芒鈧珺次元官网网址� one of Turkey's top conglomerates that is involved in pharmaceuticals and building products 芒鈧珺次元官网网址� told reporters near the scene that the Russians on board the helicopter were clients who had been invited to visit a ceramics produce fair. They were being transported to visit the company's factory near the town of Bozuyuk, some 200 kilometres (120 miles) south of Istanbul.

The Turkish national headed the company's operations in Russia, he said.

The Associated Press