The United Nations estimated Tuesday that in the past month, more than 123,000 Rohingya people have fled Myanmar for Bangladesh, attempting to escape what has been called the "deadliest outbreak of violence in the area for decades."

The Rohingya, who have been described as the world's most persecuted people, are an impoverished, stateless, mostly Muslim ethnic minority. They live primarily in the western Rakhine state of Myanmar (formerly Burma), and have been fleeing the nation for decades, but a recent military crackdown has triggered allegations of atrocious human rights abuses and an influx of refugees arriving in Bangladesh.

"Many of those who have fled describe troops and Rakhine Buddhist mobs razing their villages and killing civilians in a campaign to drive them out," BBC reports.

An estimated 20,000 people "are stranded in the 'no man's land' between the two countries, having been denied entry by Bangladesh border guards," and another 400,000 stateless Rohingya people are trapped in conflict zones in western Myanmar, according to the Guardian.

The trip to reach the border has proven deadly. Last week, at least 46 Rohingya people—including 19 children—were killed when a boat bound for Bangladesh capsized. However, despite the risks, Mohammed Abdiker, director of operations and emergencies at the U.N.'s Migration Agency, said on Tuesday that there are "clear signs that more will cross into Bangladesh from Myanmar before [the] situation stabilizes" and without more international support, "suffering will continue."

Border camps in Bangladesh are "running out of space," and the U.N. Refugee Agency said on Tuesday that "those who have made it to Bangladesh are in poor condition. Most have walked for days from their villages—hiding in jungles, crossing mountains and rivers with what they could salvage from their homes. They are hungry, weak, and sick."

Although the U.N. has been able to provide some relief supplies to the refugees in border camps, in an exclusive report on Monday, the Guardian revealed that "Myanmar has blocked all United Nations aid agencies from delivering vital supplies of food, water, and medicine to thousands of desperate civilians at the center of a bloody military campaign against the country's Muslim Rohingya minority."

The move was immediately condemned by rights groups, and Tirana Hassan, Amnesty International's director for crisis response, said: "Rakhine state is on the precipice of a humanitarian disaster. Nothing can justify denying life-saving aid to desperate people. By blocking access for humanitarian organizations, Myanmar's authorities have put tens of thousands of people at risk and shown a callous disregard for human life."

Offering broad criticism on Monday, Pakistani education activist and Nobel Peace Prize recipient Malala Yousafzai joined other human rights activists in calling on Myanmar's leader, Aung San Suu Kyi, also Peace Prize recipient, to put an end to the inhumane treatment of the Rohingya in Myanmar.

My statement on the #Rohingya crisis in Myanmar: pic.twitter.com/1Pj5U3VdDK

— Malala (@Malala) September 3, 2017