A police officer and a civilian on Saturday have killed by PKK terror attack in Derik district, in Turkey's southtern Mardin province.The terrorists reportedly attacked a police lodging with a bomb-laden vehicle, which was previously parked in front of the building.They started harassment fire around 9 pm local time, and police immediately returned fire. The bomb-laden vehicle was detonated by terrorists when police officers staying in the lodging came outside with their weapons.Initial reports stated that a police officer and a civilian who was passing by were killed by the explosion.Security forces have closed all entries and exits to Derik district and carry out operations.The PKK is recognized as a terrorist organization by Turkey, European Union and the United States.Heavy civilian casualties are a result of a shift in the PKK's strategy, which is to engage security forces in urban areas and cities. Digging ditches, erecting barricades and killing security personnel while shopping or asleep, are some of the activities of this newly adopted strategy, which has been implemented since the PKK ended the cease-fire on July 11, 2015.The terrorist organization has also damaged historical sites, including mosques and cultural artifacts.