Video report by ITV News Correspondent Debi Edward
At least 9,000 Rohingya died in Myanmar in just one month earlier this year, according to new figures.
Médecins Sans Frontières (MSF) says its latest surveys of refugee settlement camps in Bangladesh show the staggering extent of attacks against the Rohingya people - with at least 6,700 deaths attributed to violence.
An estimated 730 of those were children below the age of five.
The figures are far higher than Myanmar's official figure of 400, as authorities blame violence on "terrorists" and vehemently deny any wrongdoing.
MSF spokeswoman Ruby Siddiqui told ITV News the figures were "shocking":
MSF medical director Dr Sidney Wong said the findings, dated between August 25 and September 24, were a "clear indication" of widespread violence targeted at Rohingya.
"We met and spoke with survivors of violence in Myanmar, who are now sheltering in overcrowded and unsanitary camps in Bangladesh," he said.
"What we uncovered was staggering, both in terms of the numbers of people who reported a family member died as a result of violence, and the horrific ways in which they said they were killed or severely injured.
"The peak in deaths coincides with the launch of the latest 'clearance operations' by Myanmar security forces in the last week of August."
On August 25, Myanmar's military, police and local militias launched the operation to clear Rohingya in Rakhine state, in response to attacks by the Arakan Rohingya Salvation Army.
Around 647,000 Rohingya are thought to have fled Myanmar into Bangladesh since then.
Dr Wong said he believes the true numbers could be much higher, as other refugee camps in Bangladesh had not been included in the survey.
In addition, he said, many families had never made it out of Myanmar - which meant nobody was able to report whether they had survived, and how they died if they did not.
"Currently people are still fleeing from Myanmar to Bangladesh and those who do manage to cross the border still report being subject to violence in recent weeks," he added.
"With very few independent aid groups able to access Maungdaw district in Rakhine, we fear for the fate of Rohingya people who are still there."
Overall, MSF said, the survey found:
At least 9,000 deaths between August 25 and September 24
At least 71.7%, or 6,700, of these were due to violence
That includes 730 children aged under five
Gunshots were the cause of69% of violent deaths
9% were burned to death in their houses
5% were beaten to death