A worker was killed Saturday in an attack by Kurdish rebels on the construction site of a military outpost in southeastern Turkey, Anatolia news agency reported. One worker was killed and three were injured when members of the outlawed Kurdistan Workers Party (PKK) targeted the military building site in Semdinli town in Hakkari province, the agency reported quoting local officials. The attack prompted Turkish security forces to launch a broad incursion into the area to flush out the rebels. In a similar attack on Thursday, one soldier was killed and another was injured in the same Semdinli area, a frequent scene of clashes between the rebels and Turkish forces. The PKK, listed as a terrorist organization by Turkey and by much of the international community, took up arms in Kurdish-majority southeastern Turkey in 1984, sparking a conflict that has claimed some 45,000 lives. Fighting usually escalates in spring as snow melts along the mountainous Iraqi-Turkish border, enabling rebels holed up in rough terrain to launch attacks more easily.