The UN's human rights envoy to Myanmar has expressed disappointment today over a lack of government effort to tackle problems underlying violence between Buddhists and Muslims in the western state of Rakhine. '<br/>'<br/>Yanghee Lee, on her fifth mission to the country, said she saw little improvement in the situation for Muslim ethnic Rohingya in Rakhine, where the army has been accused of human rights violations on a vast scale during counterinsurgency operations following an attack on police outposts along the border with Bangladesh last October.<br/>'<br/>Completing a 12-day fact-finding tour, she also said the government prevented her from visiting several areas in Rakhine state and in the north where there is armed conflict.