Spain's maritime rescue service has recovered the bodies of five migrants who died attempting to cross the Mediterranean Sea in a small boat.

The service says Saturday that a passing merchant ship spotted the small boat adrift Friday some 70 miles (113 kilometers) from Spain's southeastern coast. It said when rescuers reached the boat, they found that all five passengers "apparently from sub-Saharan Africa" were in an "advanced state of decomposition."

The rescue service also says 92 migrants were saved Saturday from three separate boats just east of the Strait of Gibraltar.

Each year, thousands of migrants die trying to reach European shores from North Africa in small and often unseaworthy boats, many of which belong to smugglers. So far this year, 1,808 people have died crossing the Mediterranean.