COX’S BAZAR, Bangladesh ― More Rohingya Muslims from Myanmar poured into neighbouring Bangladesh this week, with some feared drowned after a boat sank in a river during a bid to flee escalating violence that has killed at least 86 and displaced about 30,000 people.

Some Rohingya refugees have been missing since Tuesday after a group crossed the river Naaf that separates Myanmar and Bangladesh. Those who managed to enter Bangladesh sought shelter in refugee camps or people’s homes.

“There was a group of people from our village who crossed the river by boat to come here, but suddenly the boat sank,” said Humayun Kabir, the father of three children untraceable since the mishap.

Although many of those on board could swim, and were able to reach the river bank, seven people are still missing, he added, his children among them.

The Mynamar violence is the most serious since hundreds were killed in communal clashes in the western state of Rakhine in 2012, and poses the biggest test yet for the eight-month-old administration of Nobel Peace Prize winner Aung San Suu Kyi.

Soldiers have poured into the area along Myanmar’s frontier with Bangladesh in response to coordinated attacks on three border posts on Oct. 9 that killed nine police officers.

Myanmar’s military and the government have rejected allegations by residents and rights groups that soldiers have raped Rohingya women, burnt houses and killed civilians during the military operation in Rakhine.

Sirajul Islam, who arrived on Monday at an unregistered camp in Bangladesh’s southern coastal town of Teknaf, said he did not know what happened to his eight-member family after soldiers set fire to their home in Rakhine.

“I don’t know where my wife and children are,” Islam said. “I somehow was able to cross the border to save my life.”

Up to 30,000 people are now estimated to have been displaced and thousands more have been affected by the recent fighting, the United Nations has said.

U.N. agencies have not given specific numbers of fleeing Rohingyas, but aid workers told Reuters hundreds crossed the border to Bangladesh over the weekend and on Monday. [nL4N1DM3R8]

Under military lockdown, a humanitarian effort to provide food and medicines to more than 150,000 people has been suspended for more than 40 days in the area, home mostly to Rohingyas.

“Difficult as it is for the Bangladesh government to absorb large numbers, it seems to me there is no other choice, because the only other choice is death and suffering,” said John McKissick, head of the U.N. High Commissioner for Refugees office in the southern resort town of Cox’s Bazar.

“For now, the only thing that can be done is to assist and protect them.”

Many people in mainly Buddhist Myanmar see the country’s 1.1 million Rohingya as illegal immigrants from Bangladesh.

Shawkat Ara, a girl in a refugee camp in Teknaf, who had arrived from Myanmar by boat on Tuesday, said she hoped to return one day and locate missing relatives.

“When there is peace in our country, I will go back and I will try to find out about my father and uncles,” she said.