KABUL (Reuters/AFP) - Partial Afghan election returns released on Saturday showed President Hamid Karzai extending his lead in last weeks vote, but still falling short of the 50 per cent needed to avoid a run-off. The closest challenger to Karzai warned that the future of his country was at stake as the allegations grow of fraud in the poll. Afghanistan has been on tenterhooks since the Aug 20 election, with official results coming out in slow drips, Karzais camp claiming victory and his main rival, former foreign minister Abdullah Abdullah, alleging widespread fraud. With results from about a third of polling stations tallied, Karzai leads Abdullah by 46.3pc to 31.3pc. The latest results extend Karzais lead substantially from earlier partial figures, but they still suggest he would face a run-off, which must be held if no candidate wins more than 50pc, scheduled for early October. Western diplomats have said it is still too close to say whether Karzai can avoid a second round. Southern provinces, which largely support Karzai, have been late to report. They are also the areas where many of the fraud allegations have been concentrated, and where Taliban violence and threats were most successful in scaring away voters. Washington has in particular expressed concern about the return of Uzbek ex-militia chief Abdul Rashid Dostum, viewed by Western officials as a warlord, who came back from apparent exile in Turkey days before the election to campaign for Karzai. A spokesman for Dostum said on Saturday that he had again left the country, returning to Turkey. Meanwhile, allegations of vote-rigging in the elections gathered momentum Saturday as the main challenger said he would not accept a compromised outcome and Western powers called for transparency. The Electoral Complaints Commission (ECC) has received more than 1,000 complaints, including 790 on election day, many lodged by Abdullahs office. Abdullahs threat not to accept the result if it was shown to have been rigged raises the prospect of violence, even though all sides have vowed to keep a lid on dissatisfaction among their supporters. In an interview with British newspaper The Daily Telegraph, Abdullah said he was shocked at the extent of the apparent vote-rigging and would examine all legal avenues to counter what he called state-engineered fraud. If that proved unsuccessful, he said he would refuse to recognise the election, adding: I think if the process doesnt survive, then Afghanistan doesnt survive. If it worked, all well, if it didnt we will not accept the legitimacy of the process and then this regime will be illegitimate. Abdullah, who has presented media with what he said was evidence of fraud by Karzais camp, said it remains to be seen if the ECC was strong enough to disallow suspect votes and ballot boxes.