A vast forest fire has forced the evacuation of hundreds of people from their houses in Tuscany, with firefighters Tuesday battling to extinguish flames fanned by fierce winds. Around 600 hectares in total have been consumed by the blaze, chief Pisan firefighter Ugo D'Anna told a local television station, adding that while it was now contained it would take some hours to put out. The fire was "almost certainly arson," he said. Two water-bombing planes and 80 firefighters, helped by 50 volunteers, were tackling the blaze, which broke out overnight Monday near Pisa in northern Italy, briefly threatening the towns of Calci, Montemagno and San Lorenzo e la Torre. Some 700 inhabitants were evacuated as olive trees burned in their groves and the sky across the area turned a deep orange, according to an AFP photographer at the scene. On Tuesday the region's four firefighting helicopters were grounded due to the strong winds. "It's unbearable to see a natural heritage which developed over decades burned to the ground in a few hours," Environment Minister Sergio Costa said in a statement. Tuscany's governor Enrico Rossi declared a state of emergency and said evacuated locals would not be able to return for 24 hours while risk assessments were carried out. "The firefighters were our angels. It was an apocalyptic scene and thankfully they saved us," one evacuee was reported as saying by Italian media. "I really hope the blaze was carelessness because I can't bear to think it could have been such an evil act by such a twisted mind." Local prosecutor Alessandro Crini said an investigation into arson was underway, as "the fire began at night and on a relatively cool evening".