The inflatable boats were intercepted as they were crossing the Strait of Gibraltar. The immigrants, mostly from sub-Saharan Africa, were given blankets and taken to the Spanish port of Tarifa, the maritime services said in a statement.

The Strait of Gibraltar separates Spain and Morocco by around just 15 kilometres  making it one of the key smuggling routes for illegal immigrants crossing into Europe from the African continent.

Thousands of illegal migrants from Africa regularly attempt to cross from Morocco into Spain on makeshift boats each year.

Authorities fear many of those who attempt the crossing by sea die of thirst, hunger or exposure.

Last October at least 16 African migrants died while trying to reach Spain from Morocco by boat.