The U.S.-led coalition and Afghan forces have killed a suspected Taliban commander and three of his fighters in the country's south, while six other rebels died in a clash with Afghan police, officials said Monday.

Payenda Mohammed (search), who was thought to have led about 150 rebels, was killed in a fierce battle in Kandahar province on Wednesday, said U.S. military spokesman Col. James Yonts. He was believed responsible for numerous rocket attacks, ambushes and other guerrilla-style assaults.

At least three other militants were killed and 15 wounded in the fighting, in which A-10 warplanes and attack helicopters bombed caves along a ridge where the militants had sought shelter and had stashed weapons, Yonts said Monday. No Afghan or coalition troops were wounded.

Afghan and coalition forces have stepped up attacks in recent months in an attempt to prevent the Taliban from subverting landmark legislative elections on Sept. 18. Hundreds of suspected rebels have been killed.

Elsewhere, Afghan police fought a two-hour gunbattle with about 30 Taliban rebels, believed responsible for an ambush on a civilian vehicle earlier in the day in Shahjoy district of southern province of Zabul.

Ali Khail, spokesman for the provincial governor, said on Monday that six of the rebels were killed, while the others, including their leader, Mullah Lutfullah (search), fled. He said the police suffered no casualties in the fighting Sunday.

Yonts said American forces are doing all they can in Afghanistan to locate Usama bin Laden but he cannot say when the Al Qaeda leader will be captured.

"When will he be captured? ... I can't give you a date, but I can tell you this: Everyone remembers 9/11," Yonts told reporters in Kabul.

Bin Laden has long been suspected to be hiding in remote mountains between Afghanistan and Pakistan, but no hard evidence has emerged on his exact whereabouts. Some 20,000 U.S. forces are deployed in Afghanistan, hunting fugitive Al Qaeda and Taliban leaders.

Despite the recent rash of attacks, Afghan President Hamid Karzai (search) said Sunday he was confident the Sept. 18 elections will be peaceful.

"There will be threats ... but that would not deter the Afghan people from participating. We will soon have a parliament," Karzai told reporters.

But other Afghan officials, as well as U.S. authorities, have warned that the violence may worsen ahead of the elections, the next key step toward democracy after a quarter-century of fighting.

American military commanders have prepared elaborate security plans to safeguard the voting, saying Taliban rebels are throwing all their resources into disrupting the polls.

Last week, militants attacked a U.S. military convoy 25 miles east of Kabul, wounding three American soldiers, a U.S. military statement said Sunday.

Attacks on the U.S. military so close to Kabul are rare and Friday's assault occurred less than a week after a roadside bomb in the capital exploded near a convoy of U.S. Embassy vehicles, wounding two American staff members.

In southern Uruzgan province on Sunday, gunmen ambushed a parliamentary candidate, Adiq Ullah, as he was driving, killing him and wounding two others in his vehicle, said provincial Gov. Jan Mohammed Khan. He blamed the Taliban for the murder.

Ullah's killing brings to four the number of candidates killed so far. Four election workers have also been murdered and several election offices have been rocketed.