Fierce wildfires have forced the evacuation of thousands of residents and are threatening some of Spain's most precious natural parks, including one that is a Unesco World Heritage Site, officials said.
Fires on the Canary islands of La Gomera and Tenerife led to the evacuation of more than 4,000 residents and the cutting off of many roads as precautionary measures, the regional government said.
By mid-afternoon on Sunday, residents were still not allowed to return to 18 towns and villages that had been evacuated, eight on the popular tourist island of Tenerife and 10 on La Gomera, the government said.
Regional official Nancy Melo said there was evidence the fire on La Gomera was started deliberately because "it had two focal points three kilometres (two miles) apart that began burning vigorously within a short space of time from each other".
A statement said firefighting crews working on the islands were "finding it difficult to limit the spread of fire".
"We are living through hell, we have asked the central government for more resources with which to fight the fire," said Casimimo Curbelo, local government leader of La Gomera.
At the heart of his island lies Garajonay National Park, which experts say contains woodlands that have survived since the Tertiary age, 11 million years ago. Garajonay was declared a World Heritage Site by the UN cultural agency in 1986 and is a very rare example of the type of humid subtropical forest that once covered almost all of Europe before the arrival of humans.
"We are heartbroken, we feel we have lost our beautiful, irreplaceable island," said Armenia Mendoza, a wine producer who was one of the first residents to report the outbreak of the fire to emergency services. The fire was raging out of control, said Mendoza, who wept and added that it was "almost unthinkable a native islander could have done this on purpose".
Water-carrying aircraft that doused flames when the fire first broke out there a week ago were sent away after officials decided the outbreak was under control. But the blaze was rekindled by winds and high temperatures, Ms Melo said.
Fires in Spain and other Mediterranean countries char hundreds of thousands of acres every year.