A group of Rohingya refugees making the hazardous journey had been adrift for more than two weeks in a damaged boat without food and water, activist groups say.
At least 100 ethnic Rohingya are stranded in a boat off India's Andaman Islands and as many as 16-20 may have died of thirst, hunger or drowned, said two Myanmar Rohingya activist groups.
The stranded boat was approached by five Indian ships late on Tuesday, a source said.
Each year many Rohingya, members of a Muslim minority, risk their lives boarding rickety vessels to escape deadly violence in Myanmar and squalor in Bangladesh refugee camps. Many attempt to reach Malaysia.
A spokesperson for the Indian Navy said he did not have any details to share. A spokesperson for the Coast Guard did not respond to a request for comment.
"We estimate that probably as many as 20 have died… some from hunger and thirst, and others jumped overboard in desperation. This is absolutely awful and outrageous," said Chris Lewa, director of the Arakan Project which works to support Myanmar's Rohingyas.
READ MORE: Sri Lankan navy rescues Rohingya refugees adrift in Indian Ocean
Asia Pacific Refugee Rights Network’s Rohingya Working Group said the group had been adrift for more than two weeks.
"We heard late last night that there were some Indian vessels approaching the boat so we are awaiting updates now,” said Lilianne Fan, chair of Asia Pacific Refugee Rights Network’s Rohingya Working Group.
"We hope that the Indian Navy or Coastguard will manage to rescue and disembark the boat as soon as possible. These people have been adrift on a damaged boat for more than 2 weeks without food and water. We have heard that up to 16 people may have already died."
Fleeing for years
Another boat, carrying more than a hundred Rohingya was rescued by Sri Lanka's navy on the weekend.
More than 750,000 members of the Rohingya ethnic group fled Myanmar following a crackdown launched by the army in the later summer of 2017 - fleeing what the UN described at the time as "textbook ethnic cleansing" and what rights groups have described as "genocide".
Rights groups have documented Myanmar security forces committing mass rapes, killings, and the burning of thousands of Rohingya homes.
Myanmar authorities have said they were battling an insurgency and deny carrying out systematic atrocities.
Groups of Rohingya Muslims have attempted to leave the camps in Bangladesh by sea to seek better life in other countries in the region.
READ MORE: Dozens of Rohingya refugees flee Myanmar, land by boat in Indonesia