Wild elephants have attacked a new camp where Rohingya refugees were sleeping, killing a woman and her three children in southern Bangladesh.

District forest official Mohammed Ali Kabir says a herd of elephants entered the Balukhali camp in Ukhiya town early Saturday and trampled tents where several refugees were sleeping.

Kabir said Sunday that four other people were injured in the attack and many others fled to safety.

Officials said the new camp was built in a forest area that was earlier frequented by elephant herds.

It was the third attack by wild elephants on the refugees in Bangladesh's Cox's Bazar district, which borders Myanmar. At least seven people died in the two previous attacks.

More than 525,000 Rohingya refugees have fled Myanmar since late August and have taken shelter in Bangladesh, since security forces in Buddhist-majority Myanmar responded to militant attacks crackdown that the UN described as "ethnic cleansing".

The World Health Organisation (WHO) has begun distributing hundreds of thousands of doses of the cholera vaccine, in an attempt to prevent a major outbreak of the deadly disease. More than 10,000 cases of diarrhoea were reported one one week alone at the start of October.