MOSCOW (AFP) - Russia's Vladimir Putin implicated Washington Thursday in the killing of Libyan dictator Muammar Gaddafi and launched a tirade against Senator John McCain in an extraordinary attack on US policies. Putin turned stone-faced when asked about a tweet from McCain -- one of Washington's fiercest critics of Putin -- warning Russia it faced an "Arab spring" revolt over the disputed December 4 parliamentary elections. "Mr McCain fought in Vietnam. I think that he has enough blood of peaceful citizens on his hands. It must be impossible for him to live without these disgusting scenes anymore," Putin said in reference to Gaddafi. "Who did this?" Putin demanded. "Drones, including American ones. "They attacked his column. Then using the radio -- through the special forces, who should not have been there -- they brought in the so-called opposition and fighters, and killed him without court or investigation." The Pentagon immediately dismissed the charge as "ludicrous". "The assertion that US special operations forces were involved in the killing of Colonel Gaddafi is ludicrous," spokesman Captain John Kirby told AFP on the sidelines of US Defence Secretary Leon Panetta's visit to Iraq.