Abdullah Abdullah, Hamid Karzai's main challenger, has called for a run-off in Afghanistan's presidential election.br br Abdullah insists the poll held two months earlier, in which he came a distant second according to unofficial results, was massively rigged in favour of Karzai.br br Amid the controversy, Afghanistan is yet to elect a new president and there is still no clear indication about whether there will be a run-off.br br Al Jazeera's Jonah Hull reports from Kabul.