COX’S BAZAR, Bangladesh (Reuters) - Rohingya Muslims fleeing a Myanmar military offensive arrived in Bangladesh on Monday with fresh accounts of violence and arson as a rights group called for sanctions and an arms embargo to stop what the United Nations has branded ethnic cleansing.

The latest wave of violence in western Myanmar’s Rakhine State began on Aug. 25, when Rohingya insurgents attacked police posts and an army camp, killing about 12 people.

The Myanmar military response has sent more than 410,000 Rohingya Muslims fleeing to Bangladesh, escaping what they and rights monitors say is a campaign aimed at driving out the Muslim population.

Buddhist-majority Myanmar rejects that, saying its forces are carrying out clearance operations against the insurgents of the Arakan Rohingya Salvation Army, which claimed responsibility for the August attacks and smaller raids in October.

Hundreds of refugees traveled by small boats to an island on the southernmost point of Bangladesh late on Sunday and on Monday, telling of persecution and destruction.

“The army came and they burned our homes, they killed our people. There was a mob of Rakhine people too,” said Usman Goni, 55, after he stepped off a boat with his seven children and wife, clutching two sticks tied in rope and a sack.

Many of the refugees have spoken of ethnic Rakhine Buddhist civilians joining the Myanmar army in its attacks. Myanmar denies that and has blamed Muslim insurgents for the violence.

Myanmar has largely sealed the area off to aid workers and reporters.

Rights groups say satellite images show about 80 smouldering Muslim villages. They have seen evidence of arson attacks on Buddhist villagers, but on a much smaller scale.

SUU KYI TO SPEAK

Most of the new arrivals said their villages had been torched on Friday, when huge clouds of smoke were clearly seen over Myanmar.

“There’s nothing left,” said a Nurhaba, 23, who said she was from a village close to Maungdaw town.

About a million Rohingya lived in Rakhine State until the recent violence. Most face draconian travel restrictions and are denied citizenship in a country where many Buddhists regard them as illegal immigrants from Bangladesh.

Myanmar government leader and Nobel laureate Aung San Suu Kyi has faced a barrage of criticism from abroad for not stopping the violence.

The military remains in charge of security and there is little sympathy for the Rohingya in a country where the end of army rule has unleashed old animosities. The military campaign in Rakhine State has wide support.

Suu Kyi is due to speak to the nation on Tuesday about a crisis the United States has called a “defining moment” for her country.

U.S. Deputy Assistant Secretary of State Patrick Murphy is due in Myanmar this week.

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He will travel to Sittwe, the capital of Rakhine State, to meet government officials and representatives of different communities, including Rohingya, but he is not seeking to travel to the conflict zone in northern Rakhine State.

‘STRATEGICALLY SOUND’

Human Rights Watch said Myanmar security forces were disregarding world condemnation and the time had come to impose tougher measures that the generals could not ignore.

It called for governments to “impose travel bans and asset freezes on security officials implicated in serious abuses; expand existing arms embargoes to include all military sales, assistance, and cooperation; and place a ban on financial transactions with key ... military-owned enterprises”.

Slideshow ( 27 images )

For years, the United States and Western allies imposed sanctions on Myanmar in support of Suu Kyi’s campaign for democracy. Its response was to forge closer ties with China.

U.S.-Myanmar ties have been improving since the military began withdrawing from government in 2011, and paved the way for a 2015 election won by Suu Kyi’s party.

A Trump administration official said the violence made it harder to build warmer ties, and there would likely be some “easing” in the short term, but he did not expect a return to sanctions.

“People are too invested in the last five years of thawing, which is understood by everyone to be strategically sound,” said the official, who declined to be identified.

“Long-term, the trajectory is probably tighter relations.”

In a rare expression of support for the Rohingya from within Myanmar, a group from the Karen ethnic minority, called for the military to halt its operations and for economic sanctions to be considered.

For decades of army battled autonomy-seeking Karen insurgents that sent more than 100,000 villagers fleeing to Thailand. The insurgents have now made peace.

Bangladesh is struggling to cope with the refugees and aid workers fear people could die due to a lack of food, shelter and water, given the numbers.

Bangladesh has said all refugees must go home. Myanmar has said it will take back those who can verify their citizenship.

Several thousand protesters tried to march on the Myanmar embassy in the Bangladeshi capital, Dhaka, but police kept them well back.

For an interactive on the Rohingya exodus, click: here