MADRID (Reuters) - A major forest fire in Spain"s Canary Islands was burning out of control on Sunday, forcing the evacuation of an observatory containing one of the world"s largest telescopes. Officials said the blaze had devastated 3,000 hectares (7,400 acres) on La Palma, one of seven Canary Islands off the northwestern African coast. "The fire is still out of control," a Civil Guard spokesman told Reuters. "Strong winds so far have made it difficult to use helicopters, but it seems that the situation improved in the last hours." More than 500 people, with four helicopters and two planes, were working to get the fire under control. Jose Luis Perestello, a local official in charge of firefighting, said the Roque de Los Muchachos Observatory had been evacuated as a precautionary measure but the building was not thought to be in danger. The observatory includes the William Herschel telescope, one of the largest in the world.