KABUL — Taliban threats appeared to dampen voter turnout in the militant south today when Afghans chose the next president for their deeply troubled country. Insurgents launched scattered rocket, suicide and bomb attacks that closed some polling sites.

After ten hours of voting, including a last-minute, one-hour extension, election workers began to count the millions of ballots cast across the country. Initial results weren't expected until Saturday.

Low turnout in the south would harm President Hamid Karzai's re-election chances and boost the standing of his top challenger, former Foreign Minister Abdullah Abdullah. Turnout in the north appeared to be stronger, a good sign for Abdullah.

International officials have predicted an imperfect election — Afghanistan's second-ever direct presidential vote — but expressed hope Afghans would accept it as legitimate, a key component of President Barack Obama's war strategy. Taliban militants, though, pledged to disrupt the vote and circulated threats that those who cast ballots will be punished.

A voting official in Kandahar, the south's largest city and the Taliban's spiritual birthplace, said voting appeared to be 40 percent lower than during the country's 2004 presidential election. The official asked not to be identified because he wasn't authorized to release turnout figures. Journalists reported low turnouts in Kabul compared with longer lines seen in the 2004 vote.

Militants carried out attacks around the country. Security companies in the capital reported at least five bomb attacks, and Kabul police exchanged fire for more than an hour with a group of armed men; two suicide bombers died in the clash, police said. Taliban spokesman Zabiullah Mujahid claimed five gunmen were fighting with police.

The tight security across Kabul was relaxed after polls closed, as Afghan troops and police vacated checkpoints.

Karzai, dressed in his traditional purple-and-green-striped robe, voted at a Kabul high school in the morning. He dipped his index finger in indelible ink — a fraud prevention measure — and held it up for the cameras. Presidential palace officials released a rare photo of Karzai's wife casting her vote.

"I request that the Afghan people come out and vote, so through their ballot Afghanistan will be more secure, more peaceful," Karzai said. "Vote. No violence."

Karzai, who has held power since the Taliban was ousted in late 2001 by a U.S.-led invasion, is favored to finish first among 36 official candidates, although a late surge by Abdullah could force a runoff if no one wins more than 50 percent.

The next president will lead a nation plagued by armed insurgency, drugs, corruption and a feeble government. Violence has risen sharply in Afghanistan in the last three years, and the U.S. now has more than 60,000 forces in the country close to eight years after the U.S. invasion following the Sept. 11, 2001, attacks. A U.S. service member was killed in a mortar attack in the east today, bringing to at least 33 the number of U.S. troops killed this month.

Karzai, a favorite of the Bush administration, won in 2004 with 55.4 percent of the vote, riding into office on a wave of public optimism. As the U.S. shifted resources to the war in Iraq, Afghanistan fell into steep decline, marked by record opium poppy harvests, deepening government corruption and skyrocketing violence.

The top U.N. official in the country, Kai Eide, acknowledged scattered attacks but said the election "seems to be working well."