A charity ship that rescued migrants in the Mediterranean is sailing to the Bay of Bengal to deliver food, clothing and medical assistance to Rohingya Muslims fleeing violence in Myanmar, the group's head said today.

Regina Catrambone, co-founder of the Migrant Offshore Aid Station (MOAS), said its flagship vessel, the Phoenix, suspended operations off the north African coast this week after rising tensions with Italian and Libyan authorities.

"There is another exodus (like the one in the Mediterranean) ... unfolding on the other side of the world," she told the Thomson Reuters Foundation by phone.

There were protests in India, as well as in Indonesia, against the treatment of the Rohingya. Photo: Reuters

"We want to alleviate their suffering," she said, adding that she could not provide more details until the crew arrived.

About 146,000 Rohingya Muslims have fled to Bangladesh after insurgent attacks in late August sparked clashes with security forces and provoked a military counter-offensive, the United Nations said.

The exodus has stretched aid agencies already helping those who have arrived in Bangladesh since October when Rohingya insurgents staged similar but smaller attacks on security posts.

The Phoenix will reach the Bay of Bengal in around two weeks to deliver aid and medical care, but not to rescue people from the sea as it does in the Mediterranean, Catrambone said.

Malta-based MOAS has rescued or assisted 40,000 migrants in the Mediterranean since 2014, as well as helping fleeing Rohingya in Bay of Bengal in 2016, she said.

On Monday MOAS became the fourth group to stop rescue operations in the Mediterranean as it did not want to risk having to take migrants back to Libya where they are locked up in overcrowded warehouses with little food.

"We cannot be part of this mechanism of inhumanity," Catrambone said.

"As a humanitarian organisation, we work to make sure that the people (we save) will go to a safe port ... We cannot cheat them."