Passengers aboard a Spanish ship spotted the corpses.
At least three boats sunk attempting the treacherous passage from Libya to Italy.
Researchers say this is a common "service" for desperate migrant mothers fearful of losing their jobs.
Myanmar has up to now resisted calls for it to take part in meetings on the migrant crisis.
Italian Prime Minister Matteo Renzi says leaders should stop "pretending not to see."
Several thousand migrants, many of them hungry and sick, are adrift in boats in Southeast Asian seas and governments of the region must rescue them quickly to avert a "massive humanitarian crisis," the U.N. says.
The Rohingya, a persecuted Muslim minority in Myanmar, were among the hundreds of refugees rescued in Malaysia and Indonesia this weekend.
More people have drowned in the Mediterranean this year than in the Titanic disaster.
The leader of the National Front on the U.S. immigration system and Europe's migrant crisis.
Unmanned aircraft could be used to spot migrants boats in trouble, helping to stop further tragedies.
Over 10,000 migrants arrived in the first three months of this year.
The death of up to 300 migrants in the Mediterranean has led to calls for collective action from EU member states.
Migrants were attempting to reach Italy from Libya in stormy weather, the U.N. refugee agency said on Wednesday.
The boat sent out a distress call on Tuesday, but no gunmen were found on board