Government spokesman and four-star General Khieu Sopheak has threatened to sue an NGO worker over his "false allegations" about Montagnard asylum seekers. In a Monday interview with Voice of America, Interior Ministry spokesman Sopheak denied reports that five Montagnards - a mother and father, their two young sons, and 9-month-old daughter - were arrested in Ratanakkiri on Sunday. Sopheak said authorities had only arrested "illegal Vietnamese immigrants", and called on Chhay Thy, provincial coordinator for local rights group Adhoc and the monitor who first reported the arrests, to either prove they were Montagnards or rescind the allegations. "There are no Montagnards[in the province]. I ask Adhoc to specify this clearly, or we will sue[Thy] in the court for making politically motivated allegations," he said. According to Adhoc and local villagers, 27 Montagnards remain in hiding in the province. Sopheak could not be reached for comment, while Thy said he would not back down. "I work in accordance with a human rights policy and the Refugee Convention. I just fulfil my duty; I do not work for a political party," he said, adding that Sopheak's threat was a "normal thing" that happens to human rights activists. Thy stressed that reports of the arrests on Sunday were true and confirmed by accounts from villagers and activists. He also questioned why 13 Montagnards were allowed passage to Phnom Penh in December to process asylum claims if the ministry believed that all those hiding were merely "illegal Vietnamese immigrants". The threats against Thy once again extended to social media yesterday as a Facebook account called "Lum Phatsrok", which he alleges is controlled by a senior provincial official, invited ISIS militants to "cut off" his tongue. Ignoring the threats, Thy continued to call on authorities to reveal the whereabouts of the arrested Montagnards. The family of asylum seekers have not been seen since their arrest in O'Yadav district on Sunday, and ethnic Jarai villagers in Ratanakkiri fear that they have been deported. The United Nations yesterday continued to raise concerns. "The responsible authorities are not responding to our inquiries about the arrested persons. We are very concerned about this group and will continue to liaise with the authorities to confirm their status and, if they indicate that they seek asylum, to ensure that they are able to do so," said Wan-Hea Lee, country representative of the UN Office of the High Commissioner for Human Rights. Vivian Tan, regional press officer for the Office of the UN High Commissioner for Refugees, said UNHCR would be "very concerned if people seeking asylum, including women and children, are unable to access national procedures". Provincial officials refused to comment on the arrests yesterday. Ratanakkiri police chief Nguon Koeun told the Post to "stop calling and asking me about that".