Investigations by the UN's refugee agency have confirmed that Thai authorities opened fire as they were moving Rohingya boatpeople, sparking a warning that it was now "gravely concerned" by the situation.
A statement issued last night by the UN High Commissioner for Refugees said its staff had interviewed boatpeople near the resort of Phuket as well as some 121 boatpeople who arrived in Aceh, Indonesia, four days after the incident, which reportedly took place on February 22.
"According to converging accounts, at least three shots were fired during the interception, but the information is conflicting as to whether these were warning shots or actually aimed at the passengers," the statement said.
"Survivors and local fishermen near Phuket said two dead bodies were recovered from the sea, though it was unclear if the cause of death was shooting or drowning."
Recent reports in the South China Morning Post - based on survivors' and local villagers' accounts and photographic evidence - have detailed the deaths of at least two boatpeople.
The shootings occurred when Thai military personnel tried to separate around 130 refugees between two boats. Some Rohingya refused to obey the troops' orders. When one soldier fired a warning shot, about 20 jumped overboard.
The troops then opened fire at those in the water, according to survivors and witnesses from the village of Hinlad, near the port of Kuraburi. One fisherman said he and others saw 15 to 20 corpses floating close to Hinlad soon after.
The Thai navy has denied the reports without elaboration. Thai Prime Minister Yingluck Shinawatra said government policy was to treat the Rohingya humanely and vowed to investigate.
The statement by the UN's refugee agency said it was "gravely concerned that people fleeing unrest could have been turned away and exposed to further distress in their search for safety.
"We are seeking access to such boats intercepted in the high seas," the statement added.
Agency officials have previously described Myanmar's Rohingya - a conservative Muslim minority - as some of the most persecuted people anywhere, traditionally denied normal citizenship rights, including even marriage or work, despite having lived in Rakhine state for centuries. The UNHCR estimates that around 7,000 Rohingya have taken to boats to flee in the first two months of the year, with most believed to be heading to south and southeast Asia.
About 1,800 boatpeople have been accepted on Thai soil and given shelter and assistance pending longer term solutions, the UNHCR said, which added it welcomed the move.
Some 320 people on two boats have been picked up off Malaysia in the last week, with the UNHCR saying they believed them to be Rohingya in need of international protection.
Thai authorities have also adopted a policy of "helping on" Rohingya boats caught in local waters, providing them with fuel, food and water on condition that they do not land in Thailand.
Earlier, Thai security forces operated a secret policy of towing the Rohingya out to sea in unpowered boats and casting them adrift. Hundreds died in 2008 and 2009 before the policy was exposed and repudiated.