A 12-year-old child was killed and another civilian was injured in clashes when a group of PKK terrorists attacked Turkish security forces in the Nusaybin district of southeastern Mardin province on Sunday.The two civilians were wounded when PKK terrorists opened fire at a military vehicle carrying security forces to Cizre, a town in Turkey's southeast that has been the focus of PKK attacks. The wounded civilians were rushed to Nusaybin State Hospital. One of the civilians has succumbed to his wounds.The security forces have launched an operation to capture the terrorists.The PKK -- listed as a terrorist organization also by the U.S. and EU -- resumed its 30-year armed campaign last July.Since then, more than 260 members of the security forces have been martyred and thousands of PKK terrorists killed, according to officials.