YANGON, Myanmar — The U.N special investigator on human rights in Myanmar warned Wednesday that sectarian violence could jeopardize the country's democratic reforms if it is not addressed urgently. Tomas Ojea Quintana said the government's investigation of recent violence between Buddhists and Muslims in northern Rakhine state failed to address allegations of killings of women and children. "The situation in Rakhine state might jeopardize the whole (reform) process because of the international and regional implications of the situation," he told reporters at the end of a six-day investigative mission. The United Nations says at least 48 Muslims appear to have been killed by Buddhist mobs in a village in the state's Maungdaw region. The government has vehemently denied that the violence occurred. He said he will urge the U.N. Human Rights Council to work with the government to carry out a credible investigation if the government's current probe fails to meet international standards. "An investigation conducted with the involvement and support of the international community, including in relation to technical assistance, represents an opportunity to turn the tide of impunity in Myanmar," he said. Quintana, who is concluding his six-year mandate as special human rights envoy to Myanmar, said he had seen many improvements in the rights situation, but that establishing the rule of law remains a focus of the country's transition from harsh military rule to democracy.