The explosion took place near the entrance to the town of Kocakoy, to the northeast of Diyarbakir, the biggest city of the mainly Kurdish region, Diyarbakir governor Efkan Ala told the Anatolia news agency.

Ala said the bomb was laid by "terrorists", the official jargon used to describe rebels from the outlawed Kurdistan Workers' Party (PKK).

More than 37,000 people have been killed since 1984 when the PKK, blacklisted as a terrorist group by Turkey, the European Union and the United States, took up arms for Kurdish self-rule in southeast.

The rebels have stepped up their violent campaign this year and are blamed for a number of deadly bomb attacks in urban centres this year.