At least five people have been killed after a helicopter crashed onto a motorway in Istanbul, according to Euronews.com.

Turkish media say the helicopter was carrying senior business executives.

One report says the passengers were Russian nationals.

Some witnesses say the helicopter struck a television tower in heavy fog in a district on the outskirts of Istanbul before crashing onto the motorway.

There are not thought to have been any casualties on the motorway.

The helicopter is reported to have taken off from Istanbul’s main Ataturk airport.