The bus was carrying migrants of Syrian, Afghani and Burmese origin to Ayvacık district in a bid to illegally cross into Greek island of Lesbos.
The car driver and its passenger as well as four migrants including two women and two children in the bus have died. Injured migrants were reportedly transferred to nearby hospitals.
According to witnesses, the driver smuggling the migrants in the bus have fled after the incident.
Gendarmerie found life jackets and inflatable boats in the bus luggage. The investigations into the accident continues.