Afghan election returns have put President Hamid Karzai on course for a first-round victory, but a watchdog that can veto the outcome said it had found "clear and convincing evidence of fraud" and ordered a partial recount.
The disputed results put Mr Karzai and Afghan election officials on a collision course with an international community ever more doubtful of a poll it funded and sent troops to protect.
Western officials initially hailed the August 20th election as a successful milestone, because Taliban militants failed to scupper it. Those assessments have become more guarded as evidence of widespread fraud has mounted.
The partial recount ordered by a UN-backed watchdog could delay a final result for weeks or months, keeping Afghanistan in a prolonged state of political uncertainty.
With votes from 91.6 per cent of polling stations counted, the Independent Election Commission (IEC) reported Mr Karzai ahead with 54.1 per cent of the vote to 28.3 for main rival Abdullah Abdullah, who accuses the president's team of large scale fraud.
It was the first time the commission had reported Mr Karzai on course to exceed the 50 percent threshold needed to win outright and avoid a second round. The result makes it a near mathematical certainty that when the remaining votes are counted Mr Karzai will have 50 per cent - unless ballots for him are thrown out.
A separate Electoral Complaints Commission (ECC), led by a Canadian and mainly appointed by the United Nations, has the power to do just that. It went public with accusations of fraud for the first time.
"In the course of its investigations, the ECC has found clear and convincing evidence of fraud in a number of polling stations," the body said in a statement announcing it had ordered a partial recount.
Mr Abdullah called the official tally a "tragic joke" and said it included hundreds of thousands of phoney ballots cast at "ghost polling stations" that never opened on polling day. He said it could cost desperately-needed Western support.
"It will be very difficult to justify the support of the outcome of an election, for which hundreds of millions of dollars have been spent and Nato soldiers have died, ... (if) fraud decides the outcome, not the will of the people."
Diplomats are worried at the prospect of the UN-appointed ECC being obliged to either bless or overturn a Karzai victory. They have repeatedly tried to discourage the Afghan authorities from suggesting the election is over before complaints are heard.
"There are no winners in this election until the complaints are fully investigated by the Electoral Complaints Commission and there is a partial recount as ordered by the ECC," said Aleem Siddique, a spokesman for the UN mission in Kabul.
US ambassador Karl Eikenberry told reporters: "We're looking to the IEC and Electoral Complaints Commission to rigorously carry out their legal mandate to count all votes and exclude all fraudulent votes."
The UN-backed ECC ordered the Afghan-led IEC to recount results from polling stations where one candidate received more than 95 per cent of the vote or more than 600 votes were cast.
The IEC says it has already set aside results from more than 600 polling stations that it considers suspicious.
It removed some results from its website without explanation, including those from several villages where Mr Karzai supposedly won every single vote, in some cases with exactly 400 or 500 votes cast at multiple polling stations.
Reuters