Nearly 100 Kashmiri youths, who travelled to Pakistan on valid visas for short durations, have either not come back or have disappeared after their return in last three years, raising an alarm within security agencies which fear that they could be possible sleeper cells of terror groups operating from across the border. Alarm bells rang in April last year when a group of five terrorists were killed in jungles of the border area of Handwara in North Kashmir. One of them was a local who went to Pakistan in 2018 and had not returned since, various officials from security agencies said. Between April one to six of last year, youths hailing from Shopian, Kulgam and Anantnag districts of South Kashmir were seen as part of the infiltrating groups of terrorists and all of them had travelled to Pakistan on valid documents and never returned thereafter, they said.