New Delhi - More than 300 illegal migrants were feared to have drowned off India's Andaman and Nicobar Islands in the Bay of Bengal, police and officials said Monday.

The migrants, Bangladeshi and Burmese nationals, went missing after they jumped from boats and tried to swim ashore.

At least 99 people were rescued by the Indian Coast Guard and three men were able to swim ashore.

Coast Guard officials, citing survivors, said the migrants had left some 45 days earlier for Thailand and Malaysia from Bangladesh, where they planned to work.

According to survivors, there were a total of 412 people, mostly Bangladeshis and some Burmese on six boats which were spotted by the Thai Navy after they reached Thai waters.

The migrants were detained for about four weeks and later put on non-mechanized boats with some bags of rice in the high seas to reach home, survivors told Indian officials.

They were drifting in the Bay of Bengal for 12 days before they reached the vicinity of the island group, some 1,200 kilometres off the Indian mainland.

"On Friday night one of these men swam to Hut Bay and told the authorities that many others were drifting on the sea," Ranjit Narayan, police chief of the Andamans and Nicobar Islands said over phone.

In subsequent operations, 88 people were found on a boat near the Little Andaman Island, some 80 kilometres south of state capital, Port Blair, Narayan said. Another 11 men were rescued from the sea and an adjoining island.

"Survivors have said many of those on the boats, numbering over 300, had jumped into the sea hoping to swim ashore," said Indian Coast Guard spokesman Commandant Vijay Kumar.

"While all of them are feared or missing, we will continue search operations in the nearby islands. We have also alerted vessels in the vicinity to be on the lookout for any survivors," he added.

Kumar said the survivors were in poor health as they had little food or water during the past few weeks. Police and intelligence officials were questioning the men to verify their statements.

"The survivors were provided fist-aid and medical treatment. Many of them them are being questioned to find the details of the illegal trafficking," Kumar said. (dpa)