A fourth Russian shipment of nuclear fuel arrived in Iran on Sunday, destined for a power plant being constructed in the southern Iranian port of Bushehr, the official Islamic Republic News Agency reported. The report said 11 tons of fuel arrived at the Bushehr power plant, just two days after Iran received its third Russian shipment on Friday. Russia has reportedly pledged to give Iran a total of 85 tons of fuel for the plant. The remainder of the fuel, about 40 tons, was scheduled to arrive in four separate shipments in the coming months, the report said. Iran received its first two shipments of nuclear fuel from Russia in December - after months of disputes between the two countries, allegedly over delayed construction payments for the reactor. Iran has said Bushehr, the country's first nuclear reactor, will begin operating in the summer of 2008, producing half of its 1,000 megawatt capacity of electricity. Teheran heralded the first shipment as a victory, saying it proved its nuclear program was peaceful and not a cover for weapons development as the US has claimed. The United States and Russia have said the supply of nuclear fuel meant Iran had no need to continue its uranium enrichment program - a process that can provide fuel for a reactor or fissile material for a bomb. Iran has agreed with Russia to return the spent fuel to ensure it doesn't extract plutonium to build a bomb. Iran insisted it would continue enriching uranium because it needed to provide fuel to a 300-megawatt light-water reactor it was building in the southwestern town of Darkhovin. Iranian officials have said they plan to generate 20,000 megawatts of electricity through nuclear energy in the next two decades. Russia's decision to begin shipping nuclear fuel to Iran followed a US intelligence report released earlier this month that concluded Tehran had stopped its nuclear weapons program in late 2003 and had not resumed it since. Iran says it never had a weapons program.