Half of the Rohingya children who fled to Bangladesh without their parents following a military crackdown in Myanmar were orphaned by violence, the international charity Save the Children (STC) said Thursday.

The group said there are currently more than 6,000 unaccompanied Rohingya children living in Bangladesh's southeastern city of Cox's Bazar.

STC Country Director in Bangladesh Mark Pierce said 24-hour support had been established for the unaccompanied children entering Bangladesh over the last year while workers searched for their parents.

"One year later, it is clear that for many, this reunification will never take place," Pierce said.

Read more: Solving Rohingya crisis will require 'international pressure'

The orphaned children were part of a mass exodus of Rohingya Muslims from Myanmar's Rakhine State after they were subject to a brutal army crackdown, which the United Nations has described as "ethnic cleansing."

Families split by violence

The study, the largest of its kind to be carried out in Cox's Bazar, found 63 percent of unaccompanied children were separated from their parents or main caregivers during a direct assault on their village and 9 percent as their family attempted to flee to Bangladesh. Save the Children had no information on the fate of adults in the villages. 

"We knew it was bad, but not this bad," said Beatriz Ochoa, a humanitarian advocacy manager for Save the Children in Cox's Bazar. "Even experienced child protection managers were shocked by the findings … This is going to have a profound implication on our work."

Read more: Myanmar's democracy movement 30 years on – military still calls the shots

Save the Children said that while the figures presented in its research were not statistically representative, the children were selected randomly from STC's unaccompanied and separated children caseload and it was likely that their experience mirrored those of other unaccompanied children.

Mass exodus to Bangladesh: A series of coordinated attacks on Myanmar police posts in western Rakhine State led the military to launch the violent crackdown on the Rohingya people on August 25 last year, driving more than 700,000 Rohingya into Bangladesh, including at least 370,000 children. 

Researchers from Australia, Canada and Norway in August estimated that more than 23,000 Rohingya have been killed in violence in Myanmar.

Myanmar's Ministry of Information has blamed Rohingya militants for the violence in Rakhine and claims that only 400 people have died since the conflict began, labeling the 400 dead as "extreme terrorists" who died during military "clearance operations."

Read more: Rohingya people in Myanmar: What you need to know

Persecution of the Rohingya: The Rohingya have long been subject to persecution in Myanmar. After military rule began in the country in 1962, the situation for the Rohingya worsened and government campaigns saw thousands of Rohingya pushed into neighboring Bangladesh. A new citizenship law passed in 1982 further exacerbated the situation — 135 national ethnic groups were identified but the Rohingya were not included, rendering them stateless.