Afghanistan votes in historic presidential election --- People in Afghanistan are voting for a new president in what will be the nation's first ever transfer of power through the ballot box. -- A massive security operation is under way to thwart the Taliban which has vowed to disrupt the election. -- Eight candidates are vying to succeed Hamid Karzai, who is barred by the constitution from seeking a third consecutive term as president. -- The poll has already been overshadowed by the shooting of two journalists. -- Heavy rain was falling in Kabul early on Saturday and BBC correspondents said young voters in particular were defying the conditions and the security threats. -- BBC, at: http://www.bbc.com/news/world-asia-26893972