KABUL, Afghanistan — Engine failure brought down a U.N. helicopter sent to collect ballot boxes from northeastern Afghanistan on Tuesday, injuring no one but causing a new glitch in efforts to tally the results of the country's landmark presidential election.
The accident came as a panel of foreign experts began probing irregularities in Saturday's vote alleged by rivals of front-running interim leader Hamid Karzai.
The complaints have stalled the start of vote-counting, though officials were hopeful the tally could begin Wednesday. Final results could take until late October.
The helicopter had yet to pick up any ballot boxes when it crash-landed in a snowy field in the Pamir mountains of Badakhshan province, said David Avery, chief of operations for the U.N.-Afghan body managing the vote.
The American military said one of its C-130 transport planes dropped emergency supplies, including sleeping bags and food, to the three crew members, three election workers and two police officers on board.
The group took shelter in an abandoned house, and the U.S. military said another helicopter would try to rescue them Wednesday.
Avery said the loss of the Russian-made Mi-8 would slow the recovery of ballots from Badakhshan, one of the country's most inaccessible provinces. Donkeys have also been used to bring ballot boxes from remote villages.
The helicopter was "at such an altitude that it's unlikely to be recoverable," Avery said.
The massive task of counting the results of this war-ravaged nation's first-ever Western-style vote was also being slowed by faulty paperwork accompanying some of the boxes flooding into regional counting centers, Avery said.
The tally will begin Wednesday at the earliest, and final results are not expected until late October.
Chances for a conclusive outcome were on firmer ground after several of Karzai's challengers backed away from a boycott of the vote, indicating they would accept an independent commission to probe vote-fraud charges.
Karzai is the clear favorite to win, but his ability to consolidate his rule would be undermined if the opposition refused to acknowledge the vote results.
Ethnic Tajik candidate Yunus Qanooni, considered Karzai's closest rival, said Monday he would accept an investigation by independent experts into opposition complaints that the supposedly indelible ink used to mark voters' thumbs in some polling stations could be rubbed off, allowing some to vote more than once.
There were indications another rival, ethnic Uzbek warlord Abdul Rashid Dostum, might be considering backing down as well. Dostum traveled Tuesday to Kabul from his home in the north, and his spokesman said he was considering accepting a compromise.
The candidates had a Tuesday afternoon deadline to submit formal protests.
Election officials said Qanooni and two other candidates were complaining about a shortage of ballots in some areas in addition to the problems with the ink.
U.N. spokesman Manoel de Almeida e Silva said Tuesday that two members of the panel had been appointed and had "started working today." A third member was in the "final stages of being identified."
He said it was "totally realistic" that vote-counting could begin Wednesday.
Election organizers agreed to the panel in hopes it would end a crisis begun when all 15 opposition candidates declared the boycott Saturday.
The election has been hailed as a success by U.N. officials, President Bush and other world leaders. International observers have criticized the 15, saying their demand to nullify the vote was unjustified.
A high voter turnout in Afghanistan, which never before has tasted democracy, and a failure of Taliban rebels to launch a massive attack have also been held up as proof of success.