REPUBLIKA.CO.ID, GENEVA - More than 700 people fleeing Africa and the Middle East may have drowned in shipwrecks in the Mediterranean over the last week, bringing the death toll this year to almost 3,000, according to the International Organisation for Migration (IOM) on Monday.

In the worst incident, as many as 500 migrants are believed to have died after traffickers rammed their ship off Malta's coast last week, an event that only came to light this weekend in testimony from two of nine survivors.

The survivors said the traffickers ordered the migrants to change vessels in the middle of the Mediterranean. The migrants refused, leading to a confrontation that ended when traffickers rammed the ship carrying the migrants, causing it to sink, IOM spokeswoman Christiane Berthiaume told Reuters in Geneva.

"Some 500 people were on board - Syrians, Palestinians, Egyptians and Sudanese. They were trying to reach Europe," Berthiaume said.