Members of the ethnic Rakhine Buddhist population are accused of assisting the military in a campaign of murder, rape, and arson against the Rohingya - violence the United Nations brands "ethnic cleansing".
The military's statement maintained that "illegal Bengalis" were responsible for violence in Rakhine State, using a term preferred by the majority of Myanmar to infer Rohingya are illegal immigrants from Bangladesh.
Mr Gilour, the United Nations assistant secretary-general for human rights, added: "It appears that widespread and systematic violence against the Rohingya persists".
"Myanmar army investigations found security personnel did not commit extrajudicial killings or sexually abuse and rape women and there was no unlawful detention of people, beating, killing and arson as well, " it said.
Muhith said Myanmar would "take 15 a day when there is one million", referring to the Rohingya in camps strung along the border.More news: Mystery Powerball victor claims prize amid anonymity battle
"It appears that widespread and systematic violence against the Rohingya persists", said Gilmour, stating that the violence had now shifted from "the frenzied blood-letting and mass rape of past year to a lower intensity campaign of terror and forced starvation that seems to be created to drive the remaining Rohingya from their homes and into Bangladesh".
"The nature of the violence has changed from the frenzied blood-letting and mass rape of past year to a lower intensity campaign of terror and forced starvation that seems to be created to drive the remaining Rohingya from their homes and into Bangladesh", he said in a statement, adding that new arrivals are travelling from interior Rakhine towns further from the border.
Living conditions for refugees remain extremely hard despite a growing worldwide response, but the United Nations refugee agency said the threat from elephants had emerged as a new concern.
A Rakhine Buddhist leader facing treason charges linked to deadly riots appeared in a Myanmar court on Wednesday, a case that has aggravated ethnic tensions in a region also roiled by the crackdown on Rohingya Muslims. Despite Myanmar saying it was ready to accept back refugees under an pact signed with Bangladesh in November, he added, "Safe, dignified and sustainable returns are, of course, impossible under current conditions".
"These people have fled violence at home and must be able to seek asylum in Bangladesh if they feel unsafe where they are", she said. Authorities had received information that "terrorists" linked to the August attacks on Myanmar's security posts were sheltering there, he added. "Troop movements so close to them are making things even worse", said Major Iqbal Ahmed of Bangladesh's border guard.