At least 21 North African migrants have drowned in full view of sunbathers after their boat overturned off the Canary Islands. The overcrowded vessel of around 28 passengers, capsized metres off a beach in Lanzarote.Swimmers and surfers are reported to have tried to get to the migrants, many of whom were children, as they struggled in rough waters. The Spanish coast guard says it has picked up six survivors and recovered 18 bodies from the water. At least three more passengers are still missing. In recent years Spain has seen large numbers of migrants arriving illegally by sea from West and North Africa. Last year some 9,000 people arrived illegally in the Canaries. However, thousands are believed to have died making the crossing from Africa, usually far at sea and out of sight.