KANDAHAR, Afghanistan — A suicide bombing at an outdoor dog fighting competition killed 80 people and wounded scores on Sunday, an Afghan governor said. It appeared to be the deadliest terror attack in Afghanistan since the fall of the Taliban in 2001.

A prominent militia commander who stood up against the Taliban was killed in the attack and officials said he may have been the target.

Several hundred people, including Afghan militia leaders, had gathered to watch the competition on the western edge of the southern city of Kandahar. Witnesses reported gunfire from bodyguards after the blast but it was not immediately clear how many of the casualties might have been caused by bullets.

Kandahar Gov. Asadullah Khalid said 80 people had been killed in the attack. Abdullah Fahim, a Health Ministry spokesman, said 70 were wounded.

Khalid blamed the attack on "the enemy of Afghanistan," which typically means the Taliban. The attack's apparent target, Abdul Hakim Jan, served as a commander of an auxiliary police force, a government-backed security force made of area tribesmen that is often shorthand for a local militia operating with government approval.

But a Taliban spokesman denied the militant group was behind the attack.

"That is not our work and I will not take responsibilty for it," Qari Yousef Ahmadi said.

The Taliban often claim responsibility immediately after major attacks against police and army forces — often naming the bombers — but shy away from claiming attacks with high civilian casualties.

Kandahar, the Taliban's former stronghold and Afghanistan's second largest city, is one of the country's largest opium poppy producing areas. The province has been the scene of fierce battles between NATO forces, primarily from Canada and the United States, and Taliban fighters over the last two years.

Unlike in the U.S., where star Atlanta Falcons quarterback Michael Vick was sentenced to 23 months in federal prison for his role in a dogfighting operation, dog fights are a popular form of entertainment in Afghanistan.

German shepherds, bully kuttas and Afghan mastiffs do not fight until death but rather until one dog pins another or one of the fighters runs away. The dogs have clipped ears and tails and carry the scars of battle.

The events can attract hundreds of spectators who cram into a tight circle around the spectacle. The sport was banned under Taliban rule.

The blast crumpled several Afghan police trucks and left bloodstains around the barren dirt field. Afghan soldiers donated blood at Kandahar's main hospital after the attack, said Dr. Durani, who goes by only one name.

"There are too many patients here," he said. "Some of them are in very serious condition."

Wali Karzai, brother of President Hamid Karzai and the president of Kandahar's provincial council, said the target of the attack was Jan.

Jan was the provincial police chief in Kandahar in the early 1990s and was the only commander in the province to stand up against the Taliban during its rule, said Khalid Pashtun, a parliamentarian who represents Kandahar.

"Hakim Jan is one of the important, prominent jihadi commanders in Kandahar," Pashtun said. "There were so many people gathered and of course the Taliban and al-Qaida usually target this kind of important people."

Jan was most recently appointed the commander of an auxiliary police force — a government-backed security force made of area tribesmen that is often shorthand for a local militia operating with government approval — to protect the Arghandab, a strategic area north of Kandahar.

The Taliban briefly overran the area late last year after the local leader, Mullah Naqibullah, died of heart attack.

A joint Afghan, NATO and U.S. force pushed the militants out of Arghandab. Shortly afterward, NATO's top commander in Afghanistan, U.S. Gen. Dan McNeill, visited the area to reassure local leaders of the alliance's commitment to help President Karzai's government keep the area under their control.

Suicide attacks have been on the rise in Afghanistan, but rarely have they killed so many people. Militants carried out more than 140 suicide attacks in 2007, a record number.

Faizullah Qari Gar, a Kandahar resident who was at the dog fight, said militant commanders' bodyguards opened fire on the crowd after the bombing.

"In my mind, there were no Taliban to attack after the blast, but the bodyguards were shooting anyway," he said.

The previous deadliest bomb attack came in November in the northern city of Baghlan, when a suicide bombing and subsequent gunfire from bodyguards killed about 70 people including six parliamentarians and 58 students and teachers. Investigators never determined how many of the deaths were caused by the blast and how many by the gunfire.