Muammar Gaddafi's forces were today blamed for attacking huge oil fields in Libya's east shutting down production in an attempt to block finances of rebels.Rebel spokesmen in Benghazi said, the Sarir oil-fields, the largest in Libya with a reserve of 12 billion barrels of oil and the nearby Misala field had been attacked and extensively damaged by tanks and heavy artillery of government forces.The Libyan deputy foreign minister, Khalid Kaim told reporters in Tripoli that the strike had damaged a pipeline connecting the two oil fields to Marsa el Hariga port. He described the attacks as against international law and not covered by the UN resolution.The rebels claimed that NATO warplanes had struck their tanks near Brega, killing at least 2 people and wounding 10 others.The rebels attempt came as Gaddafi's forces used heavy fire power to pound the western city of Misruta, which they have completely cut off by land route. Rebels were preparing to supply their fighters and people in the besieged city by sea, under NATO naval escort.With his forces, blunting all rebel attacks, Gaddafi in a letter to US President Barack Obama asked him to stop air strikes on his country.Later Secretary of State Hillary Clinton asked Gaddafi's forces to pull back and seize attacks. She also reiterated that the Libyan leader give up power and leave the country.