The conflicting statements underscored the difficulty of determining the credibility of the vote also hit by militant attacks that hurt the turnout. Afghan officials started gathering and tallying results Sunday in a process that could last weeks if not months.
The country's international backers praised those who voted Saturday despite bomb and rocket attacks and voiced hoped for a democratic result. A repeat of the pervasive fraud that tainted a presidential election a year ago would only erode further the standing of Karzai administration - both at home and abroad - as it struggles against a Taliban insurgency.
While the first vote counts are due to be made public in a few days time, full preliminary results are not expected until early October, and then there will be weeks of fraud investigations before winners are officially announced for the 249 parliamentary seats, which were contested by about 2,500 candidates.
The election commission has said it hopes to release final results by the end of October. But there are likely to be a host of fraud complaints in each province - which could drag the process beyond that target date. The resolution of last year's vote took months.
On Sunday, the independent Free and Fair Elections Foundation of Afghanistan said it "has serious concerns about the quality of elections," given the insecurity and numerous complaints of fraud. FEFA deployed about 7,000 people around the country, making it the largest observer of the parliamentary vote. Many international observer groups scaled back their operations from last year because of security concerns.
At least 21 civilians and nine police officers were killed during the voting, according to the election commission and the Interior Ministry, amid dozens of bombings and rocket attacks. In addition, two pollworkers were kidnapped in northern Balkh province and their bodies were discovered Sunday, Afghan election commission chairman Fazel Ahmad Manawi told reporters.
The election commission has yet to provide an overall turnout figure but it appears to have been lower than last year. The commission said Sunday that at least 4 million people voted - at least 24 percent of the country's 17 million registered voters - though they were still waiting for reports from some voting centers. Nearly 6 million ballots were cast last year, though the widespread ballot-box stuffing means it was difficult to know how many people actually voted.
Throughout Saturday's balloting, complaints that anti-fraud measures were being ignored or weren't working poured in from across the country. People said the indelible ink that is supposed to stain voters' fingers for 72 hours could be washed off. In some polling stations, observers said poll workers were letting people vote with obviously fake voter cards.
"Ballot stuffing was seen to varying extents in most provinces, as were proxy voting and underage voting," FEFA said. Yet Karzai issued a statement Sunday calling the vote an all-round success.
"President Karzai congratulates the nation of Afghanistan on its successful parliamentary election," the statement said. "This has been another positive step in strengthening democracy in our country."
He went on to call on the country's anti-fraud watchdog to thoroughly investigate all fraud complaints.
The head of the U.N. mission in Afghanistan, Staffan de Mistura, stressed how difficult it is to hold an election in a war zone like Afghanistan and said the Afghan government should be praised for managing to get people out to vote at all.
"It's almost a miracle to have an election in these circumstances," de Mistura said.
However, he said it was too early to determine whether the vote was a success, and cautioned that the combination of a low turnout in some areas and fraud allegations could threaten the results.
"That may be a toxic combination," de Mistura said.
The head of U.S.-based observer group Democracy International said the tallying and fraud-investigation process will be key to determining the election's validity.
"Right now is a pretty critical time," Jed Ober said. "They will be following up on claims and verifying them. So much remains to be seen."
Last year's presidential vote was so tainted by ballot-box stuffing and rejiggered tallies - much to Karzai's benefit - that nearly a third of his votes were thrown out.
If Afghans don't accept the results of the vote, it could have a profound effect both inside the country and with Afghanistan's international backers, who have 140,000 troops in the country and have spent billions trying to shore up Karzai's administration.
Abdullah Abdullah, the runner-up to Karzai in the 2009 poll, has suggested there could be unrest if voters feel disenfranchised, and that candidates installed despite accusations of fraudulent voting could lead to a rubber-stamp parliament in the hands of the government.
However, an election perceived as legitimate could go some way to building public faith in a democratic system which has struggled to take root since the hardline Taliban regime was ousted in a U.S.-led invasion in 2001. The election drew a wide array of candidates, and at least in key urban centers, campaigning was vigorous and citizens on Saturday voiced resolve in voting despite the threat of militant attack.
Violence continued on Sunday, with three rockets fired a meeting of senior officials in southern Kandahar province which was intended to rally support against the Taliban. The closest landed about 40 meters (45 yards) away from the meeting in Arghandab district, attended by the provincial governor and Karzai's brother Ahmad Wali Karzai, who chairs the provincial council. No one was hurt.
In the north, an insurgent rocket attack killed six children in Ali Abad district of Kunduz province, the Interior Ministry said without providing further details.
Meanwhile, NATO forces said they killed seven insurgents in an attack Saturday targeting a Taliban commander at a village compound in volatile Nangarhar province in the east.
Ghafor Khan, the district police spokesman, said five people were killed and two wounded in the attack. He said investigators were determining whether the casualties were insurgents or civilians. NATO said its initial reporting was that no civilians were killed or hurt.
Afghan officials have repeatedly warned that civilian casualties undermine anti-insurgency efforts.
NATO said three of its service members died in attacks in Afghanistan on Saturday. Two died in a bomb attack in the south and another in an insurgent attack in the north. Their nationalities were not disclosed.
Associated Press writers Rahim Faiez and Dusan Stojanovic in Kabul, and Mirwais Khan in Kandahar contributed to this report.