A record number of migrants have been rescued in the Atlantic Ocean off Spain's Canary Islands this year, according to the Spanish coastguard.

Reuters reported that the coastguard found two dead bodies among those rescued from four boats off El Hierro, the smallest and most westerly of the Canary Islands.

A further two people died in hospital later, according to the Spanish Civil Guard, which also participated in the rescue.

There has been an increase in arrivals since September as milder weather and calmer seas have made the crossing from Africa more feasible.

The Spanish Interior Ministry reported on Thursday that 30,705 undocumented migrants had reached the Canary Islands in the first 10 months of this year, an increase of 111% from the same period last year.

In 2006, when other routes to Europe were blocked, 31,678 migrants arrived on the Canary Islands during the full year.

Last year, 43,290 undocumented migrants arrived in Spain by sea from the Canary Islands.

There are around 100 km (60 miles) between the archipelago and Africa's west coast. In recent years, migrants from Senegal and other African countries have increasingly used its seven islands to reach Spain, fleeing conflict or looking for a better life.

There will be additional emergency housing for about 3,000 migrants in military barracks, hotels, and hostels, according to the Spanish government