PARIS (Reuters) - Up to 30 people may have been killed by a fire which has raged since Wednesday in a tunnel under Mont Blanc, western Europe‘s highest mountain, a senior official told a French radio on Friday. Nine bodies have been recovered so far, authorities said. But regional prefect (senior government delegate) Pierre Breuil told France-Info radio on the spot: "there are more cars than we thought in the section of the tunnel where the fire is centered. "Our revised calculations are that, unfortunately, there may be as many as 30 dead but we won‘t know for sure until we can reach that spot," he said. The radio said the tunnel roof at that spot had caved in, the road‘s asphalt had melted and temperatures in the confined area were still around 1,000 degrees centigrade. The tunnel, which links France and Italy, has been closed since the fire began aboard a food truck for still unspecified reasons. The fire spread from the Belgian-registered truck to at least eight other lorries on the Italian side of the 11-km (seven-mile)-long tunnel. Rescuers said intense heat in the tunnel caused paint on the trucks to blister and tyres to explode. Thick smoke badly hampered the rescue work. The driver of the truck, which carried flour, wheat and margarine, was unhurt. The tunnel fire is the second disaster to hit the French Chamonix region in recent weeks, after avalanches swept through the Alps. A fire on a lorry being carried into the Channel Tunnel on a Shuttle carriage in November 1996 caused 200 million pounds ($326.4 million) damage to the undersea tunnel and forced its closure for months but no lives were lost in that incident. ($1=.6127 Pound)