MILAN — Survivors said as many as 240 people died in two shipwrecks off Libya, the UN refugee agency reported Thursday, bringing this year’s toll to more than 4,220 migrants dead or missing in risky Mediterranean Sea crossings, the highest count on record.

Carlotta Sami, a spokeswoman for the refugee agency in Italy, said 31 survivors of two shipwrecks who arrived on the southern Italian island of Lampedusa reported that the rubber dinghies they were traveling in had capsized Wednesday in heavy seas shortly after leaving Libya.

The first dinghy — which carried around 140 people, including 6 children — sank when wooden planks laid at the bottom broke. Twenty-nine people were rescued.

In a separate operation, two women found swimming at sea told rescuers that 128 other people had died in their wreck.

In both cases, most people on board appeared to have been sub-Saharan Africans.

Associated Press