By Amy Sawitta Lefevre
BANGKOK (Reuters) - Nearly 6,000 Rohingya Muslims have arrived in Thailand since October, when sectarian violence flared in Myanmar's western Rakhine state and displaced tens of thousands of people, a top Thai security agency said on Thursday
Entire communities of Rohingyas are languishing in makeshift camps in Myanmar, without access to healthcare or clean water, according to the Medecins Sans Frontieres (MSF) aid group, while Thailand has promised humane treatment for the 5,899 who have arrived on its shores.
"Those detained will continue to be treated as illegal and given only basic care in line with humanitarian practices," said Dittaporn Sasamit, a spokesman for Thailand's Internal Security Operations Command (ISOC).
"The Foreign Ministry is negotiating with other countries to take them on and is seeking (Myanmar) citizenship papers for them so they can move on," he said.
Myanmar's reformist government has been criticized for its treatment of Rohingyas and its poor handling of clashes with ethnic Rakhine Buddhists in June and October. The Rohingyas came off worst in a statewide spree of machete and arson attacks.
Many Rohingyas arrived in predominantly Buddhist Myanmar as laborers from what is now Bangladesh under British rule in the 19th century, grounds the government uses to deny them citizenship.
Most of the estimated 800,000 Rohingyas in Myanmar are regarded by authorities as illegal immigrants from Bangladesh, which does not recognize them either. The United Nations has referred to them as "virtually friendless".
Thousands of Rohingyas flee from Myanmar each year on rickety boats seeking refuge and jobs in Thailand, Malaysia and Indonesia, but the number has swelled since the unrest.
MSF said its relief work was being hindered by accusations of bias in favor of the Rohingyas.
"Repeated threats and intimidation by a small but vocal group within the Rakhine community have severely impacted on our ability to deliver lifesaving medical care," MSF General Director Arjan Hehenkamp said in a statement.
Britain's Parliament on Tuesday backed a motion calling for the U.N.-mandated observers in Rakhine state.
Rights groups have often criticized Thailand for its handling of Rohingya migrants and its deportation process, which leaves many illegal immigrants open to abuse by authorities.
Thai security forces discovered almost 1,400 Rohingyas during raids in the south of the country last month and 1,752 have been detained for unlawful entry.
More boats are expected to sail from Myanmar in the coming months, according to New York-based Human Rights Watch.
(Editing by Martin Petty and Robert Birsel)