BANGKOK - More than 500 Burmese Rohingya and Bangladeshis are missing since December after being sent back into the sea by the Thai Navy, a Rohingya-dedicated group said yesterday.

The Navy denied the allegation of inhuman action and the government has promised to investigate the case.

The Navy was accused of pushing as many as 992 boat people back into the sea between December 18 and 30 after they were captured on Thai territorial waters in the Andaman Sea, according to the Bangkok-based Arakan Project.

The vast majority of the boat people are stateless Rohingya from Burma's Arakan state and might have left Burma or Bangladesh by boats to seek a better life.

The Indian coast guard rescued 107 of them in Little Andaman on December 27. More than 300 people had jumped into the sea when they spotted a lighthouse, and were believed to have drowned.

Another group of 580, arrested around December 30, was put into four boats whose engines were removed, then towed together and abandoned in the high sea, it was alleged.

Of this group, one boat with 193 onboard was rescued in Indonesia's Sabang Island in Aceh on January 7, and another boat with 150 onboard was rescued in Tillanchang Island, Andaman and Nicobar of India, on January 10. Two boats with a total of 237 people are reportedly missing, the Project said.

"So there remained some 500 people missing and they might have died," said Arakan Project coordinator Chris Lewa.

An unverified report said that a Thai fishing boat had rescued 81 people from an engineless boat in the sea and returned them to the military-controlled Koh Sai Daeng (Red Sand Island) but no official has confirmed the report so far.

Prime Minister Abhisit Vejjajiva yesterday met Thai human-rights defenders who urged the authorities to stop pushing the refugees back into the sea and find other ways to deal with them.

Foreign Minister Kasit Piromya told reporters in Pattani his government took seriously the allegation of human rights abuses against the Rohingya boat people. He said he planned to meet the ambassadors of Bangladesh, India, Burma, Malaysia and Indonesia to address this problem, which should be understood in the wider context of human trafficking.

President of the Rohingya Human Rights Association, Mohammad Noor Shim, said it was very rare the Burmese Rohingya suffered ill-treatment from Thai authorities as they were normal migrants who fled home to seek better life.

They mostly prefer Malaysia to Thailand as they could live comfortably among the Muslim community there, he said.

However, there are some 10,000-15,000 Rohingyas living in Thailand currently and some Thai authorities fear their linkage to Muslim insurgents in the deep South.