Updated

Police said Thursday that they rescued about 500 migrants from Libya after a small fire broke out on their boat miles (kilometers) off the Italian coast.

Police patrol boats spotted the boat and were escorting it toward the small island of Lampedusa when the fire began, Maj. Fabrizio Pisanelli said. The migrants were moved onto the Italian patrol boats and taken to the island.

The group of sub-Saharan Africans included 36 women and nine children.

Another boat carrying 208 migrants arrived in Lampedusa the night between Wednesday and Thursday, said Pisanelli.

Hundreds of would-be migrants have died since the exodus from Libya began earlier this year, including 250 who drowned off the Italian coast last month.

Witnesses reported another ship carrying 600 broke apart and sank near Libyan capital, Tripoli, on May 6, with the death toll unknown.

The medical humanitarian organization Doctors Without Borders sent a letter to European leaders involved in the NATO-led military operations in Libya, urging them to accept people fleeing the conflict. The open letter, published Thursday by several European newspapers, accused European countries of "neglecting the victims of the war to which they are a party."

"The words and the actions of our leaders, presented against a backdrop of the battle against illegal immigration, actually restrict access to Europe for the victims of war," said Unni Karunakara, the organization's international president. "This political cynicism is shameful."

In all, about 12,500 migrants fleeing conflict in Libya have arrived in Italy since the end of March.

International organizations have raised alarm over the immigrants' conditions in Lampedusa, which is closer to northern Africa than it is to the Italian mainland. Lampedusa has been overcrowded with immigrants, who at some points outnumbered the small island's resident population.