At least 60 people have been killed in an attack by Turkish forces against the Kurdistan Workers’ Party(PKK) militants in Turkey’s southeast, a report says. Security forces raided the basement of a building in the district of Cizre in southeastern Sirnak Province on Sunday evening, Turkish Radio and Television Corporation (TRT) reported. According to the military, several high-profile terrorists had been holed up in the basement. According to earlier reports, several dozen civilians had also been trapped in a basement for two weeks amid heavy fighting in Cizre. It was, however, not known if it was the same basement. Turkish activists, including prominent scientists, condemned the attack, describing the situation in the area as an “utter human tragedy.” They said the Turkish military’s operation against the PKK had targeted civilians trapped in the area. The activists called on the authorities to rescue the people, and denounced the attacks as “collective punishment.” Turkish Foreign Minister Mevlut Cavusoglu, however, had accused the militants of using civilians as a “human shield.” The PKK launched an insurgency against the central government in Turkey in 1984. So far, more than 40,000 people have been killed in the conflict. Turkish forces have killed almost 700 PKK militants since mid-December 2015, according to the Turkish military. Violence between the militant group and the Turkish army increased last July, and shattered a fragile two-and-a-half-year ceasefire between the two sides.