On the same day, 12 migrants arrived in waters off the Spanish territory of Ceuta in northern Morocco on board jet-skis, with one - a 28-year-old man from Guinea - drowning before he could be rescued, authorities said.
Over the past few years, migrants from North Africa and the Middle East have tended to go from Libya to Italy or through Turkey to Greece.
The shift may be because migrants are finding the Spanish route safer.
'If so, that's a big change'.
In contrast, some 13,200 migrants came to Greece this year - more than 11,700 of whom arrived by sea - down from 176,906 in total the previous year.
He added that the boats crossing the short but choppy sea to Spain were much smaller than those launching from Libya to Italy.
This is a different tactic to many migrants arriving from Libya, who are often packed onto leaky, overloaded boats, with the intention of summoning aid as quickly as possible.
They are all minors in their teens and, while they did not have any ID on them, are thought to be from Morocco, police were quoted as saying.
The teenagers will be taken to migrant reception centres, where they can apply for asylum in Spain.
While migrants often camp in crowded tent ghettos upon arrival, a great many disperse throughout Western Europe over a period of time. "And others are fine and recover quickly", he said.
Ceuta and Melilla have the EU's only land borders with Africa, and as a result, they are entry points for people desperate to get to Europe.
On Tuesday, Spanish police found 30 Moroccan and Algerian migrants, ten of which were children, hidden in fairground vehicles in the enclave city.
Spain and Morocco agreed yesterday to close the Tarajal post to freight traffic for a week because of recent migrant crossing attempts.