A boat crammed with more than 500 refugees, likely Rohingya and Bangladeshis, has been found off the coast of Penang island in northern Malaysia.
An official said that the overcrowded boat is full of desperate people and it is too dangerous to board it.
Thousands of Bangladeshis and Rohingya, a long-persecuted minority in Burma, have become victims of human traffickers who promise them safe passage to Malaysia.
But in recent weeks the traffickers have abandoned their human cargo and set them adrift in the sea off Malaysia and Indonesia.
Some estimates put their number at 6,000.