Legal activist Robert Sann Aung told The Irrawaddy that he was first approached on Dec. 19 last year by a man wearing civilian clothes in the airport in Bhamo Township, Kachin State, on the way back to Mandalay. The man claimed to be from Military Intelligence, he said, but gave no evidence of the claim. Robert Sann Aung, a former political prisoner, tried to "ignore the man's many questions." Since then, he added, the man has waited for him at the airport and followed him until he boarded his connecting flight on four separate occasions. He said people have come near his home, watching him twice a week for a while, as well as to his local teashop. He has been receiving explicit photos, crude, insulting texts and threatening phone calls-some from international numbers-from men and women, mostly between 10 p.m. and 12 a.m. Many of the calls warn him not to reform Burma's military-drafted 2008 Constitution, he said. In one of them, he was threatened with: "Aren't you afraid to die? You will be the next person who will be killed." "They may have intended to scare me and stop me from sleeping," he said. "I turn off my phone every night during that time. I was worried I wouldn't make it to work in the mornings." The lawyer has made posts on Facebook suggesting where the Constitution should be amended and has also given a media interview in which he advocated for constitutional reform. "I will keep saying it, and I will not stop," he said. "I will do my job as a citizen of the country." Robert Sann Aung, who has been imprisoned six times for his peaceful political and human rights activities, is hesitant to report the threats to authorities. In addition to believing that they would not listen to him, he says that the authorities might be connected to the intimidation and increased surveillance in the past few months. He added that it was difficult to identify who was making the phone calls, which would hinder his attempt to file a complaint at the police station. Amnesty International released a statement on Wednesday urging the authorities to take immediate steps to ensure the lawyer's safety, investigate the threats, and hold those responsible to account. The human rights activist is especially concerned about his safety as his work often involves traveling. "It is difficult to know when and where they are waiting to kill me," he added. National League for Democracy legal adviser U Ko Ni was shot dead as he held his grandson at Rangoon International Airport. His work included reforms to the Constitution. To date four people have been arrested in connection with the killing and are currently on trial, however, a fifth suspect, Aung Win Khaing, a former lieutenant colonel in the Burma Army, remains at large. Robert Sann Aung was disbarred in 1993 for defending peaceful political activists. Since his lawyer's license was reinstated in 2012, he has continued to represent human rights defenders, student activists, protestors of a contested copper mine and people whose land has been confiscated by the military.