The trio were abducted by Kurdistan Workers' Party (PKK) rebels around 6:00 pm (1500 GMT) Thursday from the site near the town of Silvan in Diyarbakir province, a brief statement from the provincial governor's office said.

It was not immediately clear why PKK militants targeted the workers.

The group has in the past kidnapped soldiers, policemen, local politicians, tourists and journalists, among others, but it is a rare tactic.

In 2008, the rebels held three German mountineers hostage for almost two weeks, in a bid to pressure Germany to end a crackdown on PKK supporters on its soil.

Blacklisted by Ankara and much of the international community as a terrorist organization, the PKK picked up arms for self-rule in Turkey's southeast in 1984, sparking a conflict that has claimed some 45,000 lives.