At least four asylum seekers were killed when their boat capsized Tuesday off the coast of Lanzarote in the Canary Islands. Twenty-eight survivors were rescued. It’s the latest tragedy to occur on the perilous route from West Africa to the Canary Islands, which have become a flashpoint in the ongoing refugee crisis as the number of people arriving to the Spanish archipelago by sea has increased more than tenfold over last year. Last month, 140 people drowned off the coast of Senegal after their boat caught fire en route to the Canary Islands. Spain said last week it would help set up temporary camps for 7,000 asylum seekers.