Policeman Mehmet Uyar was sitting in front of a tea house in the Cinar district of the southeastern Diyarbakir region late Wednesday when unknown gunmen opened fire from a car, the Anatolia and Dogan news agencies reported.
Both the policeman and one civilian passer-by named as Osman Caran later died of their wounds in hospital overnight, the reports said. Another civilian was wounded.
Both Anatolia and Dogan said that according to their information the attack was carried out by the Kurdistan Workers Party (PKK), which has waged an insurgency against Turkish forces for over three decades.
The PKK has largely observed a ceasefire since 2013 but over the last week deadly attacks on the security forces blamed on the militants have occurred almost daily.
Meanwhile, in the town of Cizre in the southeastern Sirnak region one suspected PKK member was killed when militants opened fire on a police post and the security forces opened fire in response, Anatolia said.