MADRID — The authorities in Spain and Morocco extended a search-and-rescue operation at sea on Sunday after recovering the bodies of at least 20 African migrants a day earlier off Melilla, a Spanish enclave in northern Africa.
Most of the bodies, spotted on Saturday by a Spanish passenger boat that had sailed out of Melilla, were recovered by the Moroccan authorities. One was found in a separate location by a Spanish police boat and was taken to Melilla, where an autopsy was to be performed.
Rescue boats began patrolling “a wider radius” on Sunday with the support of a Spanish police helicopter, said Irene Flores, a spokeswoman for the Spanish government in Melilla, amid fears that the strong winds and currents that made the seas dangerous in the past few days would lead the bodies to drift farther.
The authorities have not been able to determine exactly when the tragedy occurred, Ms. Flores said, nor do they know the exact route the migrants were following. Melilla, an enclave of about seven square miles, is roughly 100 miles from the Spanish mainland and attracts many seeking the promise of life in Europe.
It has a land border with Morocco, and refugees try to enter Spain by that border, often by climbing over fences. While migrants continue to climb those fences, as well as ones separating Morocco from Spain’s other enclave in North Africa, Ceuta, the Spanish authorities are grappling with an increase in attempted sea crossings spurred in part by a clampdown on other migratory routes across the Mediterranean.
The number of migrants reaching Spain via the Mediterranean almost tripled to nearly 22,000 last year, while reported drownings off the Spanish coast nearly doubled, according to a report released in January by the International Organization for Migration, a United Nations agency.
The report showed a big drop in the number of drownings, however, after a deal between the European Union and Turkey shut a main route along the eastern Mediterranean into Greece.
Some of the recent tragedies suggest that migrants are using new routes to reach southern Europe, often with the assistance of criminal gangs, according to migration experts. On Friday, the United Nations said it was investigating a sudden rise in the number of Pakistani migrants trying to make the perilous sea crossing to Europe, after a smuggler’s boat foundered off Libya, leaving 90 people feared drowned.
In November, the Spanish authorities put about 500 Algerians who had crossed the Mediterranean by boat into a prison, rather than placing them in a detention center for migrants, before deporting them back to their country.