KABUL - President Hamid Karzai and 40 other candidates will appear on the ballot for president this August in a crowded political lineup Afghanistan's electoral commission chief on Saturday called "shameful."

Karzai is considered the clear front-runner to win Afghanistan's second presidential election since the 2001 U.S.-led invasion toppled the Taliban regime. His strongest challengers in the Aug. 20 vote include former Finance Minister Ashraf Ghani and former Foreign Minister Abdullah Abdullah. Two women are also among the 41 candidates.

In announcing the final list of candidates, Azizullah Lodin, the head of Afghanistan's election commission, said he believed that many of the candidates were not qualified but said he had no power to remove them from the ballot.

"I personally feel ashamed that when I ask someone are you literate, and he says no. I ask if he has a professional background, and he says no. I ask if he was a mullah in a mosque, and he says no. And now he comes and registers himself and he wants to be president of Afghanistan. This is really shameful," Lodin told reporters.

During the country's first post-Taliban presidential election in 2004, 18 candidates ran for president. Karzai won in the first round with 55 percent, while the second placed finisher, Yunus Qanooni, the current speaker of the lower house of parliament, won 16 per cent. Qanooni is not running this year.

A separate commission examined the original list of 44 candidates and removed two, though Lodin did not say why. A third candidate dropped out.

Lodin said the commission still faced potential hurdles with the remaining candidates. Afghanistan's constitution says presidential candidates must only hold citizenship in Afghanistan and not be a dual citizen. But Lodin said the commission has no mechanism to properly screen candidates for that qualification.

U.S. and other NATO forces are pouring into the country to help secure remote election sites and ensure a smooth voting process as violence in the country skyrockets.

In the latest violence, a suicide car bomber hit a fleet of fuel tankers intended for a NATO base in southern Afghanistan, killing eight Afghans and wounding 21, officials said Saturday.

The attack in Helmand province late Friday burned six fuel tankers parked outside the town of Gereshk, said Dawood Ahmadi, the governor's spokesman. The trucks had been headed to a large NATO base primarily housing U.S. and British troops.

The attack killed eight Afghan drivers or their assistants, said Abdel Ahad Khan, the Gereshk district chief. Twenty-one people were wounded, he said.

Militant attacks have risen steadily the last three years and have reached a new high. U.S. Gen. David Petraeus said Afghanistan saw 400 insurgent attacks during the first week of June, including ambushes, small-arms attacks, assaults on Afghan infrastructure and government offices, and roadside bomb and mine explosions.

In comparison, attacks in January 2004 were less than 50 per week.

The top UN representative in Afghanistan, meanwhile, told NATO defense ministers in Brussels that there is "an urgent need to review the operations of special forces" -- comments that appear to be aimed at U.S. operations that have caused many of the civilian casualties in Afghanistan.

"We cannot eliminate civilian casualties, but we cannot afford mistakes that lead to the loss of civilian lives, the alienation of the population and media headlines month after month that overshadow all the positive trends," Kai Eide told the ministers on Friday, according to a copy of his remarks the UN released Saturday.

"The political costs are simply disproportionate to the military gains."

The Afghan government says a battle between U.S. forces and Taliban militants in Farah last month killed 140 Afghan civilians, though the U.S. says no more than 30 civilians and between 60 and 65 militants were killed.

The NATO-led International Security Assistance Force on Saturday announced that one of its soldiers was killed by a roadside bomb in southern Afghanistan on Friday. No other details, including the soldier's nationality, were released.