Kandahar's provincial governor said on Monday that the death toll in the country's deadliest suicide attack rose to more than 100 victims with several dozen others injured.
"According to our new information, the death toll for yesterday's suicide attack has gone up to more than 100 people," Assadullah Khali said.
He said about 80 deaths were registered by provincial hospitals, while the remains of 20 others were taken directly from the site of Sunday's attack by their relatives.
The health ministry said 72 deaths and 75 wounded victims were registered in their hospital records.
The attack in Arghandab district, once the stronghold of Taliban leader Mullah Omar, about 10 km north of Kandahar city, was the deadliest since the ouster of the Taliban regime in late 2001.
Haji Abdul Hakeem Jan, former Mujahideen commander during the Russian invasion, along with hundreds of local villagers had gathered in an outdoor area outside of Kandahar city to watch dogfights when a bomber detonated his explosive belt among the crowd, officials said.
Hakeem Jan, who was one of the leaders of Alokozai tribe, one of the biggest Pashtun tribes in the area, was killed along with his more than 30 militia fighters, in the blast.
After the death of Mullah Naqeebullah, the former chief of Alokozai tribe in the district, who died of heart attack last year, Taliban penetrated the district in a bloody fight between the Taliban fighters and Afghan government forces backed by NATO-led Canadian forces.
Hakeem Jan was pivotal in pushing the Taliban militants out of the district late last year, and he was appointed commander of auxiliary community police forces to contain the militants in the district.
Afghan authorities could not say if the attack was against him or the spectators of the dogfight, a popular pastime banned by the Taliban as un-Islamic.
Taliban spokesman Qari Mohammad Yousif Ahmadi denied any involvement. He blamed local disputes among the tribes for the attack.
Witnesses in Kandahar also said that many people were killed and wounded when the "panicky" Hakeem Jan's bodyguards opened fire on the crowd following the blast, a claim that authorities have yet to comment on.
The NATO-led International Security Assistance Force (ISAF) also said it would assist the authorities, if required.
"We are following this situation very closely and I have directed ISAF forces in southern Afghanistan provide maximum support to the Afghan authorities in dealing with this tragedy," Major General Marc Lessard, ISAF commander for southern region said.
The attack also sparked widespread condemnation. President Karzai, who is currently on an official visit in Doha, called it an "unislamic" and "inhuman" act.
"This attack is yet another tragic reminder of the insecurity in Afghanistan that is undermining concerted attempts by the government of Afghanistan to rebuild the country after decades of war with the assistance of the international community," a statement from the office of UN Secretary General Ban Ki-moon said Monday.
"The contrast between those who take innocent lives so brutally and senselessly and those working with Afghanistan's government and people to build a better future, could not be more stark."
Kandahar province is the birthplace of the Taliban militants, who are still entrenched there six years after being ousted from power by a US-led military invasion.