Bangkok: Thai police shot dead a Rohingya Muslim from Myanmar on Monday during a dramatic mass escape of detainees from an immigration camp in southern Thailand, police said. Police Lieutenant Colonel Noppadon Rakchart said 21 Rohingya fled the Phangnga Immigration Detention Centre at about 1am after sawing through an iron bar in their communal cell. One was shot dead and three arrested after throwing stones and punches at police and immigration officers who gave chase, said Noppadon. The other 17 escaped. Tens of thousands of Rohingya "boat people" have fled poverty and persecution in western Myanmar since religious violence erupted there in 2012. Many headed for Malaysia but often got waylaid at human trafficking camps in the jungles of southern Thailand or arrested by the authorities. Most Rohingya are stateless and unrecognised by the two countries, Bangladesh and Myanmar, they call home. This complicates repatriation, which can lead to lengthy spells in overcrowded Thai detention centres, which Rohingya often try to escape. The latest attempt was triggered by "stress and homesickness," said Noppadon. "They have been inside for almost a year." The Rohingya was killed because "he resisted arrest and attacked the police", Police Major General Worawit Parnprung, Phangnga police chief, told Reuters. "The police had to defend themselves," he said. The Phangnga detention centre had held 28 Rohingya, all of whom illegally entered Thailand by boat, he said. The number of migrants leaving Myanmar and Bangladesh by boat in the past year plunged after both countries cracked down on human smugglers and traffickers. Thai police launched a sweeping operation against gangs in May 2015 after the bodies of 30 suspected migrants were found in jungle graves near the Malaysian border. Myanmar's Aung San Suu Kyi asked to be given "enough space" at the weekend to address the plight of the Rohingya population, as visiting US Secretary of State John Kerry pressed the Nobel peace laureate to promote respect for human rights.