In the largest of several rescue operations last week, a boat carrying 53 people was spotted on Friday by a ferry off the coast of Andalusia in southern Spain, local emergency services said.
The discovery of boats loaded with migrants has gathered pace over the past week as traffickers apparently take advantage of good weather and calm seas in the area, which lies opposite the Moroccan and Algerian coastlines.
Another 41 people were rescued off the Canary Islands in the Atlantic Ocean last week, officials said.
Tens of thousands of people fleeing conflict and poverty in the Middle East and Africa make the perilous journey across the Mediterranean every year to try to reach Europe.
And in a series of maritime dramas in the dying days of 2014, traffickers abandoned two "ghost ships" in the Mediterranean carrying hundreds of migrants, mostly from Syria, who were later rescued by Italian authorities.
The United Nations has described the Mediterranean Sea as the deadliest route in the world with more than 3,400 people perishing during journeys in 2014, out of more than 207,000 who attempted the dangerous crossing.
The number of migrants hoping to reach Europe via the Spanish exclaves of Ceuta and Melilla also soared last year, many of them scrambling over border fences from Morocco.