Border police patrol in Arakan State apprehended a vessel carrying 28 people in the Bay of Bengal on Sunday (5 March) afternoon, who the authorities say had illegally entered Burmese territorial waters from St. Martin’s Island of Bangladesh, reports The Irrwaddy.

Those arrested said that they were from Internally Displaced People’s (IDP) camps of Thae Chaung and Baw Du Ba, located on the outskirts of Sittwe. They explained that some within the group had crossed over to Bangladesh by boat for medical treatment, and others had been working in Bangladesh for almost four months.

According to Myanmar police and a statement released by the State Counselor’s Office Information Committee, the 28 people are being detained.

Five of them are reportedly children, and are believed to be aged between 13 and 15 years.

Police Major Kyaw Mya Win, the head of the police in Maungdaw Township, the authorities which held the individuals, said, “We occasionally apprehend some people who have come back from Bangladesh.”

The IDPs, who are Muslims, need official permission from the authorities to travel, particularly from Arakan State’s immigration department and also the camp management committee.

In April 2016, 18 IDPs were killed and 19 rescued after a boat capsized near Thae Chaung, where one IDP camp was located. They were coming from Pauktaw Township to purchase commodities in Sittwe. It was unclear if IDPs on the boat had received permission from the authorities to make the journey.