RAWALPORA, Kashmir — Mohammad Ishaq Lone got a call from the Indian Army one February night, ordering him to meet soldiers at an outpost near his house in Kashmir. It was only after he was hauled off to a brightly lit room, bound and beaten that he discovered why.

A soldier began by punching him in the face, drawing blood, Mr. Lone said. Another smacked him with a metal rod and began demanding that he disclose the whereabouts of his brother, who had left home months earlier to join militants waging a campaign to separate Kashmir from Indian rule.

Mr. Lone, a pharmacist with two young children, begged them to stop, saying he did not know where his brother had gone. He recalled screaming for help before losing consciousness.