Migrants head back to Morocco after crossing into Ceuta by sea amid mass crossings of migrants on foot and by sea from Morocco into Spanish territory, in Ceuta, Spain, Aug. 1. Reuters-Yonhap

CEUTA, Spain — Spain on Saturday installed a 500-meter-long (1,600-foot) barrier on the sea border between its North African territory of Ceuta and neighboring Morocco after tens of thousands of migrants breached the frontier earlier in the week.

At least 67 migrants died, including some who drowned and others who were killed in a stampede to cross a breakwater barrier, the Spanish government said Saturday. The sudden arrival of 50,000 to 60,000 migrants in the territory on Thursday and Friday sparked a humanitarian crisis and reignited the immigration debate in Europe and beyond, though most of the migrants soon went back.

Critics of Spain’s socialist government, notably right and far-right politicians, seized upon the dramatic images of crowds storming into Ceuta, which sits on the Strait of Gibraltar at the entrance to the Mediterranean Sea and has been a Spanish possession since 1580. Spain’s migration policy has focused on granting legal status to workers lacking authorization who entered the country before 2026 to boost its economy, in contrast with the anti-migration and pro-deportation policies promoted across much of the EU and in the U.S.