The accident also left 11 people injured, two of them in serious condition.
At least seven people have been killed after a bus collided with two trucks in the eastern Turkish city of Agri.
The accident also left 18 people injured, two of them in serious condition, Turkish Health Minister Fahrettin Koca said.
"Seven of our citizens lost their lives in a bus that caught fire after overturning," the Turkish Recep Tayyip Erdogan confirmed in an address on Monday.
Images on state television showed the charred wreck of the three vehicles after the crash near the town of Tutak.
A total of 22 people had been on the bus, according to the Anadolu news agency.
Huge flames and black smoke had initially covered the motorway, but the fire was later extinguished by the authorities.
Initial investigations suggest that the crash occurred after an initial accident involving two trucks triggered a chain reaction.
The incident also came just one day after a separate bus accident in northern Turkey left three people dead and 32 others injured.