Three soldiers were killed in clashes with PKK terrorists in southeastern Mardin province on Thursday.According to the Anadolu Agency, security forces killed seven PKK terrorists during clashes, which took place in Dargeçit district of Mardin province.The operation is still underway.Turkey's southeast has been the scene of significant military operations since December against the PKK-designated as a terrorist organization by Turkey, the U.S., and the EU-which renewed its terrorist campaign against the Turkish state in July 2015.Since then, more than 280 security forces personnel and thousands of PKK terrorists have been killed in operations across Turkey and northern Iraq.