The BBC has spoken to Rohingya Muslims maimed after apparently stepping on landmines as they fled Myanmar (Burma).
A boy of 15 being treated in Bangladesh lost both legs while a woman at the same hospital said she had trodden on a landmine after being fired on.
The area was mined in the 1990s but Bangladeshi sources say Myanmar's army recently planted new mines - an allegation denied by Myanmar officials.
More than 300,000 Rohingya have fled a brutal security crackdown in Myanmar.
On Monday UN human rights chief Zeid Raad al-Hussein said that a "cruel military operation" was taking place, calling it "a textbook example of ethnic cleansing".
The Rohingya, a stateless mostly Muslim minority in Buddhist-majority Rakhine, have long experienced persecution in Myanmar, which says they are illegal immigrants.
Bangladesh's Prime Minister, Sheikh Hasina, is due to visit one of her country's main refugee camps for Rohingya. She said earlier that Myanmar had to solve a problem of its own making.
The White House has called on Myanmar to respect the rule of law and end the displacement of civilians.
Aung San Suu Kyi, Myanmar's de facto leader, is facing mounting criticism for failing to protect the Rohingya.
'Suffering so much'
On Sunday the human rights group Amnesty International accused the authorities of laying landmines at border crossings used by fleeing Rohingya.
Bangladeshi government sources made the same allegation speaking to Reuters news agency last week.
The hospital visited by the BBC has seen an influx of people with landmine injuries, doctors say.
The 15-year-old boy, Azizu Haque, arrived with his legs destroyed. His brother, in another hospital, suffered the same fate, his mother says.
"Their injuries are so bad it's as if they are dead," she told the BBC. "It's better that Allah [God] takes them, they are suffering so much."
The injured woman, Sabequr Nahar, says she fled Myanmar because the military had been targeting her community, and she was crossing the border with her three sons when she stepped on a landmine.
"We'd been fired on, shot at, and they planted mines," the 50-year-old said.
Horrific injuries - by Reeta Chakrabarti, BBC News, Bangladesh
Azizu Haque's body has been devastated by a blast, his legs gone, and parts of his torso also injured. His doctor is visibly emotional when he talks of trying to save him - he doesn't expect to be successful. Azizu has a rare blood type, and the hospital has no blood bank, and has run out of donors.
Next door in the women's ward, Sabequr Nahar is a tiny, exhausted figure. She says she crossed the Myanmar border behind her three sons - they got through unscathed.
It is unclear who laid the traps that caused these injuries - and when - but the condition of these people nevertheless raises questions about the Myanmar government's version of events.
How the did the violence start?
The violence began on 25 August when Rohingya militants attacked police posts in the northern state of Rakhine, killing 12 security personnel.
The attacks triggered a vast security operation that has drawn international criticism.
Rohingya who have fled Myanmar say villages have been burned and civilians attacked in a brutal campaign to drive them out.
The UN Security Council said it was looking to meet on Wednesday to discuss the violence after Sweden and the UK requested a closed-door meeting on the "deteriorating situation" in Rakhine state.
Bangladesh is already host to hundreds of thousands of Rohingya who have fled previous outbreaks of violence in Rakhine.
Existing refugee camps are full and the new arrivals are sleeping rough in whatever space they can find, reports say.
The Rohingya are extremely unpopular inside Myanmar. On Sunday, police fired rubber bullets to break up a mob attacking the home of a Muslim butcher in Magway region in central Myanmar. One protester was quoted by AFP news agency saying it was a response to events in Rakhine.
How much pressure is there on Suu Kyi to speak out?
Five Nobel peace Laureates have accused her of showing "indifference" to the Rohingya's plight.
In an open letter issued by the Nobel Women's Initiative, they say Ms Suu Kyi has a "personal and moral responsibility to uphold and defend the rights" of Myanmar's citizens.
The letter is signed by Mairead Maguire, Jody Williams, Shirin Ebadi, Leymah Gbowee and Tawakkol Karman, who were awarded the Nobel peace prize between 1976 and 2011.
"How many Rohingya have to die; how many Rohingya women will be raped; how many communities will be razed before you raise your voice in defense of those who have no voice?," they ask in the letter.