The device was detonated by militants of the outlawed Kurdistan Workers Party (PKK) as the vehicle was passing the road near Turkey's border with Iraq, the sources said.
Turkey's largely Kurdish southeast has been rocked by violence following the collapse of a 2-1/2-year ceasefire between the state and the PKK in 2015.
The autonomy-seeking PKK took up arms in 1984, and more than 40,000 people have died in the conflict. It is considered a terrorist organisation by Turkey, the United States and the European Union.
A Turkish military vehicle was hit by an improvised explosive device in the southeastern province of Hakkari, killing one soldier, security sources said on Monday.