SRINAGAR, Kashmir — A well-known journalist in Kashmir who worked to bring stability and peace to the mountainous, war-afflicted region, was shot to death on Thursday.The journalist, Shujaat Bukhari, was leaving his office in Srinagar, the capital of Indian-administered Kashmir, when three assailants riding on a motorcycle shot him and two of his bodyguards, the police said.Mr. Bukhari, 50, was hit in the head and abdomen and died shortly afterward. Both of his bodyguards were also killed. It was the first time in nearly a decade that a journalist has been murdered in Kashmir, a region that has long divided India and Pakistan.“He’s a true martyr to the cause of courageous journalism,” Shekhar Gupta, a prominent Indian journalist, wrote on Twitter.Mohammad Yousuf Tarigami, a state lawmaker in Kashmir, said by telephone that the attack was “very meticulous, well planned, targeted.”The police have released security-camera images of the attackers, but they have not been identified and no militant group active in Kashmir has claimed responsibility.Mr. Tarigami said Mr. Bukhari, one of the region’s most recognizable journalists, was targeted for a reason.“They want to send a message,” he said. “There will be a demoralizing effect on the journalist community.”Kashmir has long been embroiled in bloody conflict between Hindu-majority India and Muslim-majority Pakistan, which both claim parts of the rugged, Himalayan territory. In three decades of fighting, tens of thousands of people have been killed and injured, and in the last couple of years, the conflict has worsened.Earlier on Thursday, the United Nations released its first report on human rights violations in Kashmir, calling for an international investigation into accounts of torture, disappearances and sexual violence committed by India and Pakistan.Mr. Bukhari, who is survived by a wife and two children, was seen as a centrist and a strong voice for peace. He had been attacked in the past, including in an abduction attempt nearly a decade ago.For over a decade, Mr. Bhukari was a columnist and the editor in chief of Rising Kashmir, a leading English-language daily published in Srinagar. He published work in Kashmiri, Urdu and English and worked for many years as a correspondent for The Hindu, one of India’s major newspapers.Mr. Bukhari was also attuned to the political pulse of the region, organizing conferences in the United States and India to discuss ways to resolve the Kashmir conflict.In a February interview with The New York Times, Mr. Bukhari said that violent clashes between Indian security forces and protesters in the area had hardened many Kashmiri youth, whose views had shifted from “anti-India to hate India.”One of his last columns for Rising Kashmir concerned the Ramadan cease-fire. Mr. Bukhari wrote that the “continuous grind of violence” was becoming unbearable. The cease-fire was a “glimmer of hope for the common people,” he wrote, but there was much more ground to cover.Journalists and politicians across party lines offered condolences and said the attack was a blot on India’s human rights record.“Terrorism has hit a new low with Shujaat’s killing,” Mehbooba Mufti, the chief minister of the state of Jammu and Kashmir, wrote on Twitter. “We must unite against forces seeking to undermine our attempts to restore peace.”As night fell in Srinagar on Thursday, a group of journalists, some of them sobbing, assembled near the murder scene, trading stories about the man who had mentored so many of them. Among them was Rashid Maqbool, a longtime friend of Mr. Bukhari’s, who called him one of the most compassionate journalists he had ever known.“His killing has made a hole in my heart,” he said.