LOS ANGELES (AFP) - Pop star Shakira denied reports Thursday that she had been booked to perform at a birthday celebration for the leader of the war-torn Russian republic of Chechnya, Ramzan Kadyrov. Contrary to any misreporting, Shakira is not performing nor was she ever booked to perform a gig for the Chechen president or government, according to a Twitter message by the Colombian singer confirmed as authentic by her spokeswoman Shoshanna Stone. Last week, sources in Russias war-ravaged Chechnya region in the North Caucasus said Shakira would be attending the leaders 35th birthday celebration with other notables such as US film stars Kevin Costner, Hilary Swank and Eva Mendes, along with British violinist Vanessa-Mae.