More than 200 refugees were rescued on Wednesday by the Spanish coastguard as they attempted to make the deadly crossing from Africa to Spain, rescue services said on Thursday.

The rescue comes at a time when Spain is preparing for the arrival on a Spanish warship of 15 migrants from an Italian port following a prolonged standoff between Italian authorities and a Spanish-registered private rescue boat.

On Thursday, the coastguard said the migrants from Sub-Saharan Africa were found in three rafts in the Alboran Sea, between northeastern Morocco and southeastern Spain on Wednesday afternoon.

They were taken to Almeria and Malaga, the coastguard added.

Some 18,018 migrants have arrived in Spain so far this year by mid-August, Interior Ministry data shows. This is a decrease of 39 per cent from the same period last year.

In pictures: A day of refugee rescues in the Mediterranean Sea Show all 7 1 /7 In pictures: A day of refugee rescues in the Mediterranean Sea In pictures: A day of refugee rescues in the Mediterranean Sea A baby being taken on to MSF's Bourbon Argos ship from a boat carrying 130 migrants and refugees Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A refugee boat carrying 101 people being rescued by MSF's Bourbon Argos Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A refugee boat carrying 101 people being rescued by MSF's Bourbon Argos all images by Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A baby among refugees on a boat carrying 185 people off the coast of Libya Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea Migrants and refugees sleeping after being rescued by MSF's Bourbon Argos ship Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A crew from MSF's Bourbon Argos ship rescuing a boat carrying 130 migrants and refugees off the coast of Libya, at sunrise Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A woman in a stretcher being lifted onto MSF's Bourbon Argos ship from a boat carrying 130 migrants and refugees off the coast of Libya Lizzie Dearden

United Nations data shows irregular sea arrivals from the Middle East and North Africa to EU dropped from over 1 million in 2015 to some 141,500 people last year while nearly 15,000 people are estimated to have died or gone missing in the perilous sea voyage.