Srinagar, July 23 -- A head constable of the Jammu and Kashmir Police deployed on Amarnath Yatra security duty was allegedly shot dead by a lone terrorist in south Kashmir's Anantnag district on Wednesday, triggering a massive anti-terror operation and the detention of 2500 suspected overground workers (OGWs), officials aware of the matter said. The attack marks the first terror strike in Jammu and Kashmir since the April 22 Pahalgam terror attack, in which 26 civilians were killed at Baisaran meadow. It is also the first terror attack targeting Jammu and Kashmir Police personnel this year, they said. The incident took place around 12.30 pm at Lal Chowk in Anantnag town, officials said. According to police, head constable Aashiq Hussain Qureshi, 45, of the IRP 3rd Battalion and a resident of Beerwah in Budgam district, was critically injured after the terrorist opened fire at him from close range. He was rushed to the Government Medical College Hospital in Anantnag, where doctors declared him dead. Security forces immediately cordoned off the area and launched a search operation to trace the attacker. Following the killing, security forces launched a massive anti-terror crackdown across four districts of south Kashmir -- Anantnag, Pulwama, Shopian and Kulgam, and detained 2500 suspected overground workers (OGWs) for questioning, police said. Chief minister Omar Abdullah also condemned the killing. FULL REPORT ON PAGE 2...