Vivian Tan, the regional spokeswoman for UNHCR, told Al Jazeera on Sunday that at least 73,000 Rohingya crossed the border since violence erupted on August 25, with thousands more expected.
“Most of the people coming in are completely exhausted, some of them say they haven’t eaten in days and some are completely traumatised by their experiences,” she said.
“One woman arrived on her own after following a band of refugees across the border. When she met with the UN, she said her husband had been shot and her 18-month-old baby had been left with her in-laws.
“She has since lost contact with her family and is struggling to process what is happening,” Tan added.
In recent days, tens of thousands of Rohingya have crossed into Bangladesh to escape mass killings they say are being perpetrated by Myanmar forces.
Foreign governments and organisations fear Rohingya villages are being subject to collective punishment after an armed group on August 25 attacked police posts and an army base in the western region of Rakhine.
Myanmar officials blame the group Arakan Rohingya Salvation Army (ARSA) for the violence, but fleeing Rohingya civilians say a campaign of arson and killings by the Myanmar army is aimed at forcing them out of the country.
“We fled to Bangladesh to save our lives,” said a man who paid a smuggler hundreds of dollars to flee the fighting.
“The military and extremist Rakhine [ARSA] are burning us, killing us, setting our village on fire,” he told the AP news agency.
He said he paid 12,000 Bangladeshi taka, or about $150, for each of his family members to be smuggled on a wooden boat to Bangladesh after soldiers killed 110 Rohingya in their village of Kunnapara, near the coastal town of Maungdaw.
“The military destroyed everything. After killing some Rohingya, the military burned their houses and shops,” he said. “We have a baby who is eight days only, and an old woman who is 105.”
Aid workers told the AP news agency that a large number of refugees required immediate medical attention as they were suffering from respiratory diseases, infection and malnutrition.
The existing medical facilities in the border area were insufficient to cope up with the influx and more aid and paramedics were needed, they said.
Another aid official said on Saturday that more than 50 refugees had arrived with bullet injuries and were moved to hospitals in Cox’s Bazar, on the border with Myanmar.
Refugees reaching the Bangladeshi fishing village of Shah Porir Dwip described bombs exploding near their homes and Rohingya being burned alive.
The United Nations believes the Myanmar government’s response to the crisis may amount to ethnic cleansing and crimes against humanity.
Satellite imagery analysed by Human Rights Watch shows hundreds of buildings destroyed in at least 17 sites across Rakhine state, including some 700 structures that appeared to have been burned down in just the village of Chein Khar Li.
Myanmar authorities say Rohingya “extremist terrorists” have been setting the fires during fighting with government troops, while Rohingya have blamed soldiers who have been accused of carrying out extrajudicial killings.