At least 239 migrants are believed to have drowned in two shipwrecks off the coast of Libya, the United Nations refugee agency said Thursday, adding to the toll in what was already the deadliest year on record in the Mediterranean Sea.

Survivor accounts suggested that two crowded boats broke up just off the coast of Libya on Wednesday, U.N. refugee agency spokeswoman Carlotta Sami said. The 31 survivors were taken Thursday to the Italian island of Lampedusa, which has become a rescue hub as migrants depart Africa’s northern shores in a bid to make it to Europe.

The reports from the survivors could not be independently confirmed, but it is common for migrant ships to be filled far beyond capacity, and hundreds have perished in past sinkings. The latest shipwrecks bring the toll of dead and missing in the Mediterranean to 4,220 this year, the highest on record.

“This is an absolutely appalling figure,” Sami said.

According to Sami, the 29 survivors of the first wreck said their boat capsized after wooden planks at the bottom of their rubber dinghy broke apart several hours after departing Libya Wednesday. Survivors said they were in the Mediterranean’s cold waters for hours before being rescued.

Two survivors of a second shipwreck were rescued in a separate operation, Sami said. At least 120 had been on board their boat, which had problems immediately upon setting out and also broke apart off the Libyan coast Wednesday.

Washington Post