The bodies of four migrants have been found off southern Spain, the coast guard said Friday, adding that it was looking for 21 others still missing after their boat sank. Rescuers saved the three people from the sinking boat late Thursday, and appealed for other vessels to look out for the missing migrants, a coast guard spokeswoman said. One body was recovered from the boat while the other three were found floating nearby, she added.The vessel was first spotted around 70 kilometres (40 miles) west of Spain’s Cape Trafalgar by a passing merchant ship which sounded the alarm. Two men were found alive on board the boat while a woman was rescued from the water. The survivors said the boat had departed for Spain with 28 people on board. A helicopter was dispatched in the search for the missing migrants, which began on Thursday night. Spain is one of the largest gateways for migrants departing from North Africa and seeking a better life in Europe.