Spain's coastguard said Monday it had rescued 86 migrants from sub-Saharan Africa from a boat off the Canary Islands that had been spotted earlier in the day by a rescue plane.

Rescuers with Salvamento Maritimo had initially estimated "it could have around 200 people on board" but later said the estimate, made by the plane's crew, was incorrect, telling AFP it was "difficult to determine the number of people from the air."

Among those rescued were 80 men and six women, who would be taken to Arguineguin port on Gran Canaria, the coastguard said, indicating they were expected to arrive around 1900 GMT.

The boat had been spotted about 71 nautical miles south of Gran Canaria with the coastguard saying it was located "in an area where (the plane was) looking for a vessel that left Senegal two weeks ago".

"It's very likely it is the same boat that we've been looking for," the spokeswoman had said.