COX’S BAZAR, Bangladesh (Reuters) - Rohingya Muslims fleeing to Bangladesh from escalating violence in Myanmar face the growing danger of sickness and attempts by the Bangladesh authorities to send them home, despite a United Nations plea that they be allowed to seek shelter.

Rohingya children cross the Bangladesh-Myanmar border fence as they try to enter Bangladesh in Bandarban, an area under Cox's Bazar authority, Bangladesh, August 29, 2017. REUTERS/Mohammad Ponir Hossain

A series of coordinated attacks by Rohingya insurgents on security forces in the north of Myanmar’s Rakhine state on Friday has triggered a fresh exodus to Bangladesh of Muslim villagers trying to escape the violence.

At least 109 people have been killed in the clashes in Myanmar, according to the government, most of them militants but including members of the security forces and civilians.

The United Nations Security Council will meet behind closed doors on Wednesday, at the request of Britain, to discuss the situation in Myanmar.

Bangladesh border guards told Reuters they had sent about 550 Rohingya back across the Naf river that separates the two countries since Monday, despite an appeal by U.N. Secretary-General Antonio Guterres for Dhaka to allow Rohingya to seek safety.

Border patrols were also trying to block people from crossing the frontier.

The treatment of about 1.1 million Muslim Rohingya in Myanmar has become the biggest challenge for national leader Aung San Suu Kyi, who has been accused by Western critics of not speaking out on behalf of a minority who have long complained of persecution.

The Rohingya are denied citizenship in Myanmar and classified as illegal immigrants, despite claiming roots there that go back centuries.

The violence marks a dramatic escalation of a conflict that has simmered since October, when a similar, but much smaller, series of Rohingya attacks on security posts prompted a fierce military response dogged by allegations of human rights abuses.

The top U.N. human rights official, Zeid Ra’ad al-Hussein, called on Myanmar on Tuesday to ensure its security forces refrained from using disproportionate force, adding that the political leadership had a duty to protect all civilians “without discrimination”.

“This turn of events is deplorable. It was predicted and could have been prevented,” he said.

Myanmar’s National Security Adviser Thaung Tun said at a news conference that Myanmar had come under attack and had the full right to defend itself. He added that “security personnel have been instructed to make sure that innocent civilians are not harmed”.

NO MAN’S LAND

Bangladesh is already host to more than 400,000 Rohingya refugees who have fled Buddhist-majority Myanmar since the early 1990s. Dhaka has asked the U.N. to pressure Myanmar over its treatment of the Muslim minority, insisting it cannot accept any more.

Still, more than 8,700 have registered in Bangladesh since Friday, the U.N. said.

Hundreds of new arrivals milled around the entrance of the Kutapalong makeshift camp, the biggest unofficial refugee camp on the Bangladesh side of the border. Village elders said many of the Muslim hamlets near the border were empty, and said troops and ethnic Rakhine Buddhists had set fire to homes.

Around another 4,000 people were stranded in the no man’s land between the two countries near Taung Bro village, where temporary shelters stretched for several hundred meters on a narrow strip between the Naf river and Myanmar’s border fence.

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Reuters reporters saw women, some carrying children and the sick, fording the river, which at that location is less than 10 meters wide. Bangladeshi border guards permitted about half a dozen people at a time to cross to access a pile of donated medicines.

“We came here out of fear for our lives, but we can’t cross. So we don’t know what to do,” said Aung Myaing, from Taung Bro Let Way village, standing knee-deep in the river.

When asked about insurgents he said: “We didn’t see them, we have no relation to them. But Myanmar doesn’t distinguish between the terrorists and civilians. They are hunting all the Rohingya.”

Many Rohingya trying to enter Bangladesh were sick and at least six have died after making the crossing, an aid worker said, adding that fear of being caught and sent back meant some refused to seek help.

EVACUATION

An army source in Rakhine told Reuters that troops were hunting down insurgents across the region, clearing landmines and evacuating non-Muslims and government staff.

The government continued a mass evacuation of thousands of ethnic Rakhine Buddhists from the area, where they are a minority, to larger towns, police stations and army bases.

“All the people want to follow the army to get out of here. We have no cooking oil, we have no vegetables, we only have rice and people are in poor health,” Maung Thein Hla, a Rakhine resident stranded in the village of Taman Thar, told Reuters.

Satellite imagery analyzed by New York-based Human Rights Watch showed widespread burnings in at least 10 areas in northern Rakhine since the Friday raids, the group said.

Home Affairs Minister General Kyaw Swe said construction materials imported by international aid groups to northern Rakhine, such as steel pipes, have been used by insurgents to make weapons.

“We have found out that those things were used in handmade mines and handmade cartridges when it got to extremists and (were used to) attack our security forces,” said Kyaw Swe at a news conference.

The U.N. and international aid groups evacuated all “non-critical” staff out of the area after Suu Kyi’s office repeatedly published pictures of World Food Programme energy biscuits allegedly found at an insurgent camp and after it said it was investigating aid groups support for the insurgents in one incident.

The army source said the militants had produced a large number of landmines and were ambushing troops before quickly vanishing into the forests and mountains.

“This is their region. Any village can be their base camp - any mosque can be their headquarters,” he said. “We cannot distinguish who are insurgents or who are villagers.”