KABUL, Afghanistan-- A suicide attack on a NATO convoy killed three civilians and wounded nine others Thursday near the airport in the Taliban heartland of Kandahar in southern Afghanistan, a local official said.

Evidence of fraud in the country's recent parliamentary vote continued to mount, meanwhile, as the election commission said it had invalidated some of the ballots cast in 10 provinces and ordered partial recounts in others.

The suicide attacker detonated explosives while in his vehicle, causing the casualties, said Zulmai Ayubi, a spokesman for the Kandahar governor. He did not have further details.

A NATO spokesman confirmed one Afghan death and said the blast caused substantial damage to buildings in the immediate area and left a significant crater in the highway. NATO said the wounded civilians were medically evacuated. One coalition vehicle was damaged in the attack.

The Taliban claimed responsibility.

Coalition forces are engaged in an operation to clear areas around the city of Kandahar, a Taliban stronghold, and have said they expect heavy fighting.

A NATO service member died Thursday following an insurgent attack in the south, the military coalition said, without providing further details.

In the slow tally of results from Afghanistan's Sept. 18 parliamentary poll, election officials said they have now counted at least partial results in 20 of the country's 34 provinces. Along with the voting came myriad accusations of fraud and misconduct ranging from indelible ink that washed off voters' fingers -- thereby allowing them to vote twice -- to poll workers who ordered people to vote for certain candidates and faked voter cards.

Commission chairman Fazel Ahmad Manawi said ballots from 39 polling sites across 10 provinces had been invalidated, and ordered recounts of certain sites in another 12 provinces. The commission had previously announced recounts in seven provinces. It was not clear how many ballots were included in either the voided ballots or the recounts.

The vote was the first since a presidential election last year that was nearly derailed by widespread ballot-box stuffing and tally manipulation. That poll led many Western powers to question whether they should be supporting the administration of President Hamid Karzai with military forces and funds.

This year's elections have about 2,500 candidates vying for 249 parliamentary seats. A government anti-fraud elections watchdog has received more than 3,500 complaints of cheating or misconduct -- about 57 percent serious enough that they could affect the outcome of the vote.
Full preliminary results are expected around Oct. 9 and final results at the end of the month, following fraud investigations.