The bodies of at least 25 migrants who drowned trying to cross the Mediterranean were found washed up on a beach in western Libya near the city of Zuwara on Thursday, a Red Crescent official said on Thursday.

Hundreds of migrants have died in boat accidents this week amid a surge in departures from the North African coast toward Italy. Many of the boats are believed to have left from the shore around Zuwara and Sabratha in Libya’s northwest.

Al-Khamis Al-Bosaifi said aid workers were still recovering the bodies, many of them women, and that the circumstances in which the migrants died were not clear.

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 Sea 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 percent 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.