Over a quarter of a million Rohingya refugees from Myanmar have been jointly registered. (File)

The UN said Friday it has registered more than 250,000 Rohingya refugees in Bangladesh, providing many with their first ever identification cards and proof of their right to return to Myanmar in the future.

The UN refugee agency also said the registration could serve as a tool for law enforcement to help counter human trafficking.

"Over a quarter of a million Rohingya refugees from Myanmar have now been jointly registered and provided with identity cards by Bangladesh authorities and UNHCR," spokesman Andrej Mahecic told reporters in Geneva.

Some 740,000 Rohingya refugees fled a military crackdown in August 2017 to cross into Bangladesh where 300,000 members of the persecuted Muslim minority were already in camps.

Many Rohingya refugees who fled said there had been mass rapes and slaughters in the villages, and in a report published last September, the fact-finding mission said there were reasonable grounds to believe the atrocities amounted to "genocide".

UNHCR puts the number of Rohingya refugees currently crowded into settlements in Cox's Bazar at around 900,000, although the UN often gives a lower number than Bangladesh authorities and other aid organisations.

They are stateless, despite the fact that many of their families have lived in Myanmar for generations, since members of the Muslim minority have had their citizenship eroded over decades.

"The registration exercise, which began in June 2018, is about safeguarding the right of Rohingya refugees to be able to return home voluntarily to Myanmar in future," Mahecic said.

Myanmar and Bangladesh have signed a memorandum of understanding about repatriating the Rohingya, but so far safety fears and concerns over citizenship mean the refugees have refused to return.

The new ID cards, provided to all refugees over the age of 12, lists important information, including names, family links and fingerprints and Iris scans.

Mahecic also said that the cards list Myanmar as the refugees' country of origin.

In total, 270,348 refugees, or nearly 60,000 families, have been registered, and around 4,000 people are added to the roster each day, he said.

UNHCR's goal is to complete the process of registering all the Rohingya in Cox's Bazar by November.

Mahecic pointed out that comprehensive registration is important for improving the accuracy of data on refugees in Bangladesh, and provides authorities and humanitarians with a better understanding of the population and its needs.

He also said that the registration "can also serve as a better tool vis-a-vis the authorities to prevent and combat smuggling and trafficking".

His comment came after a rise in attempted human smuggling of Rohingya in the last few months, amid growing desperation in the camps.

Earlier this week, Bangladeshi police shot dead two suspected Rohingya human traffickers, after rescuing 103 refugees in two days about to make the perilous sea voyage to Malaysia.