Eleven migrants have reportedly drowned after their both sank off the Algerian coast of Tipaza on Sunday evening.
CIPIMD, a Spanish NGO, said that a boat carrying 16 migrants had set sail from North Africa for Spain's Balearic Islands.
Five people -- including two children -- were rescued from the stricken vessel, according to the organisation.
Last year, 3,077 migrants died or went missing while trying to reach Europe by sea, according to the UN's refugee agency.
But activists say that the number of people who died trying to reach Spain in 2021 was as high as 4,404 people -- the worst toll since 2015.
Meanwhile, officials warn that at least 478 people have already died or gone missing while trying to reach Europe since the start of January.
The UN has called for governments to develop "alternatives" to the dangerous sea routes that asylum seekers desperately use to reach European land.