The boat was spotted in the western Mediterranean off the coast of the southern region of Andalusia before dawn and 47 survivors — 30 men and 17 men — were taken to the port of Motril, a spokesman for Spain's Guardia Civil police force said.
A Moroccan coastguard vessel had earlier retrieved seven bodies and rescued 70 migrants after they got into difficulty in the Alboran Sea in the western Mediterranean, a Moroccan military source said.
The survivors, including 10 women and a baby, were found in a “very poor state” and were taken for medical treatment in Nador in northern Morocco, the source added.
The boat capsized carrying around 100 migrants headed towards Spain, according to Spanish NGO Caminando Fronteras, which added that 24 people were still missing.
Over 98,000 people have reached Europe by sea this year, including around 25,000 who arrived in Spain, according to the International Organization for Migration.
More than 1,200 migrants have died or are missing at sea after attempting to cross the Mediterranean this year, UN figures show.