A bus carrying Afghan, Pakistani and Bangladeshi migrants crashed in eastern Turkey early on Sunday, killing at least 12 people and injuring 26 others, local authorities said.

The crash occurred in Van province's Muradiye district near the Turkish border with Iran, where the vehicle caught fire after tumbling into a ditch, two local sources with information on the matter told Reuters.

The identities of those killed in the accident were not immediately clear, both sources said, adding that the owner of the bus had been detained.

Turkey has been a key transit point for migrants aiming to cross into Europe. Migrants, mostly from Iran, Afghanistan and Pakistan, regularly cross the Iranian border into Turkey on foot before being ferried west to cities such as Istanbul and Ankara.