The United Nations human rights chief says the Security Council should consider imposing sanctions on Myanmar over its treatment of the Rohingya population.

Despite Myanmar government denials, Zeid Ra’ad al-Hussein said it was clear what was really going on and said Myanmar should allow access to investigators, reports the BBC.

Thousands of Rohingya Muslims trapped by hostile Buddhists in northwestern Myanmar have enough food and will not be granted the safe passage they requested from two remote villages, a senior government official said on Tuesday.

The Rohingya villagers said they wanted to leave but needed government protection from ethnic Rakhine Buddhists who had threatened to kill them.

They also said they were running short of food since Aug. 25, when Rohingya militants launched deadly attacks in Rakhine state, provoking a fierce crackdown by the Myanmar military.

At least 420,000 Rohingya have since fled into neighboring Bangladesh to escape what a senior United Nations official has called a ‘textbook example of ethnic cleansing’.

Tin Maung Swe, secretary of the Rakhine state government, said requests from the two villages for safe passage had been denied, since they had enough rice and were protected by a nearby police outpost.

‘Their reasons were not acceptable,’ he said. ‘They must stay in their original place.’

Residents of Ah Nauk Pyin, one of the two Rohingya villages, said they hoped to move to the relative safety of a camp outside Sittwe, the nearby state capital.

About 90,000 Rohingya displaced by a previous bout of violence in 2012 are confined to camps in Rakhine in squalid conditions.

But such a move was ‘impossible,’ said state secretary Tin Maung Swe, since it might anger Rakhine Buddhists and further inflame communal tensions.

In a nationally televised speech on Tuesday, Myanmar leader Aung San Suu Kyi vowed to punish the perpetrators of human rights violations in Rakhine, but did not address UN accusations of ethnic cleansing by the military.

The Nobel Peace Prize laureate said that many Muslims had not fled and urged foreign diplomats to study why certain areas of Rakhine state had ‘managed to keep the peace’.

‘We can arrange for you to visit these areas and to ask them for yourself why they have not fled ... even at a time when everything around them seems to be in a state or turmoil,’ she said.

The Rohingya residents of Ah Nauk Pyin say they have no other choice but to stay, and their fraught relations with equally edgy Rakhine neighbors could snap at any moment.

About 2,700 people live in Ah Nauk Pyin, which sits half-hidden among fruit trees and coconut palms on a rain-swept peninsula.

Its residents said that Rakhine men have made threatening phone calls and recently congregated outside the village to shout, ‘Leave, or we will kill you all’.

On Tuesday morning, Rakhine villagers chased away two Rohingya men trying to tend to their fields, said Maung Maung, the leader of Ah Nauk Pyin.

The Rakhine deny harassing their Muslim neighbors, but want them to leave, fearing they might collaborate with militants from the Arakan Rohingya Salvation Army (ARSA), which carried out the Aug. 25 attacks.

Khin Tun Aye, chief of Shwe Laung Tin, one of the nearby Rakhine villages, said they had chased away the two Rohingya men in case they were ‘planning to attack or blow up our village’.

‘They shouldn’t come close during this time of conflict situation. People are living in constant fear,’ he said.

The Office of the United Nations Resident Coordinator in Myanmar told Reuters it was ‘aware and concerned’ about the situation and was discussing it with the Myanmar government.

State secretary Tin Maung Swe said Reuters could not visit the area for security reasons, but said the authorities were assessing needs of those living there.

‘If they need food, we are ready to send it,’ he said. ‘Don’t worry about it.’