MILAN (Reuters) - Thousands of tonnes of diesel and other fuel fouled Italy's longest river, the Po, on Thursday after pouring into a tributary from storage tanks in what authorities said could have been a deliberate act of pollution.
The Lombardy and Emilia Romagna regions in northern Italy asked Rome to declare a state of emergency to help deal with the spill in the Po and its Lambro tributary in the country's richest industrial and agricultural area.
Swift currents have hampered efforts to contain the fuel, mostly diesel.
"We are talking about 400,000 liters (106,000 gallons)," said Ferruccio Melloni, head of Emilia Romagna's civil protection agency.
The fuel poured into the Lambro late on Tuesday from storage tanks at a disused Lombarda Petroli refinery near Monza, about 30 km (20 miles) northeast of Milan, the Lombardy regional environmental protection agency said.
The fuel, which reached the Po on Wednesday, could have been released from the tanks intentionally, the agency said in a statement.
Enel SpA, Italy's biggest power company, said the fuel formed a layer between 10 and 15 cm (four and six inches) thick at its Isola Serafini hydroelectric power plant on the Po.
(Reporting by Sergio Matalucci, writing by Ian Simpson, editing by Tim Pearce)
