The bodies of at least 85 migrants who drowned trying to cross the Mediterranean were found washed up on beaches in western Libya near the city of Zuwara on Thursday, a Red Crescent official said.

Hundreds of migrants died in boat accidents last week as departures from the North African coast towards Italy surged. Many of the boats are believed to have left from the shore around Zuwara and Sabratha in Libya’s north-west.

Al-Khamis al-Bosaifi said most of the migrants appeared to be from sub-Saharan Africa, though their bodies were decomposed and it was not clear when they had drowned. The bodies of two children were among those recovered, he said.

A coastguard spokesman in Tripoli said no migrant boats had been intercepted over the past two days, with rougher seas preventing patrols.

So far this year, more than 40,000 migrants have crossed the Mediterranean from North Africa to Italy by paying people smugglers for the journey, broadly in line with a steep increase in numbers since 2014. Smugglers in Libya have exploited political chaos and lawlessness to expand their activities along routes from sub-Saharan Africa, often working with local militias.

The head of the European Union’s Mediterranean naval mission recently said that people smuggling was estimated to account for between 30% and 50% of the gross domestic product in northwestern Libya. Migrants pay smugglers hundreds of dollars for a place on boats, often flimsy inflatable craft that either sink or are picked up by international rescue missions.