Members of the outlawed Kurdistan Workers Party (PKK) carried out the attack in Bingol province, the sources said. Two of those injured were in serious condition.
The PKK, listed as a terrorist organisation by Turkey, the United States and European Union, has waged an armed campaign against security forces in the mainly Kurdish southeast since 1984, pushing for Kurdish autonomy. More than 40,000 people, mostly Kurds, have died in the violence.
Unrest has flared anew since a ceasefire collapsed in July 2015, and thousands of militants and hundreds of soldiers and police have since died. Rights groups have said about 400 civilians have also perished.
A car bomb exploded as a police vehicle passed in Bingol province.
Five police officers were killed and four others were wounded when a car bomb exploded as a police vehicle passed in southeastern Turkey on Monday in an attack that appeared to have been carried out by Kurdish militants, security sources said.
