United Nations, Feb 24 (IANS): Thousands of refugees and migrants were left abandoned at sea by their smugglers in 2015 as they crossed the Bay of Bengal, said a report published by the UN High Commissioner for Refugees (UNHCR).

Some 370 refugees and migrants died while crossing the sea, Xinhua cited the report as saying on Tuesday.

"An estimated 33,600 refugees and migrants of various nationalities took smugglers' boats (in Southeast Asia) in 2015," UN spokesman Stephane Dujarric said.

"The passengers were Rohingya and Bangladeshi nationals in the Bay of Bengal and the Andaman Sea," he said, citing information from the UN refugee agency.

The UNHCR report found that hundreds of refugees died before reaching land, primarily from starvation, dehydration, disease, and cruelty at the hands of human smugglers, rather than drowning.

However, the number of refugees making the dangerous journey dropped sharply in the second-half of 2015, said Dujarric.

The report found that the huge movement of refugees in the first months of 2016 "all but disappeared" after approximately 5,000 refugees and migrants were left abandoned at sea in May 2015.

The sharp decrease can also be attributed to "the discovery of mass graves along the Thailand-Malaysia land border and government crackdowns on smuggling networks," said Dujarric.

The report showed that the Mediterranean was not the only deadly sea crossing for refugees in 2015, Dujarric said.

Although the European refugee crisis has received significant attention, Dujarric noted that the "vast majority of refugees are being hosted in developing countries, in countries in Africa, in Asia and in the Middle East."

The responsibility to help refugees is global, he added.