France and Italy bolstered border controls on Saturday after about 60,000 people crossed into Spain's enclave in North Africa, sparking one of the largest migrant crises for the European Union in recent years.

The migrants entered Ceuta from Morocco, the enclave's regional president Juan Jesus Vivas told reporters, but by Friday evening officials said more than 48,000 had returned.

To cross into Ceuta, many swam around a small border barrier that juts out into the Mediterranean. At least 34 people died in the attempt.

The sudden influx sparked an international crisis.

France tightened checks on its border with Spain and said it would increase its police presence there fivefold to 334 officers and gendarmes by Saturday.