Spain's coast guard has found 17 dead migrants on a boat off the Canary Islands, the country's local emergency services announced on Monday.

Three survivors, two men and one woman, were transferred by military helicopter to a hospital on Tenerife.

"The three had hypothermia but were otherwise in good shape," a spokeswoman for Spain's local emergency services said.

The boat was first spotted by an Air Force plane, about 265 nautical miles from El Hierro.

A spokeswoman from Spain's maritime rescue service said that all migrants on the boat were sub-Saharan Africans. It wasn't immediately clear where the migrants had come from.

Migrant arrivals in the Canary Islands increasing

The number of migrants crossing the Atlantic from Africa to the Canary Islands is rising, despite the dangers involved.

About 3,400 people arrived in the Canary Islands from January 1 to March 31.

This incident follows another one south of El Hierro earlier this month. Four people were found dead in a makeshift boat with 23 migrants on board.

On Sunday, 100 migrants tried to reach the Spanish enclave of Ceuta from Morocco.

am/rt (Reuters, AP)