As many as 80 people were killed in a suicide bomb attack at an outdoor dog-fighting competition in Kandahar on Sunday, an Afghan official said.
Among the victims were the chief of the local police and at least six children, Kandahar Gov. Asadullah Khalid said.
Abdullah Fahim, a Health Ministry spokesman, said about 70 people were wounded.
More than 300 people, including several Afghan militia leaders, had gathered to watch the event on the western edge of the city in southern Afghanistan.
It was the deadliest attack of its kind in Afghanistan since the fall of the Taliban in 2001.
Officials blamed the Taliban and said police Chief Abdul Hakim Jan, a prominent pro-government militia commander who was fighting the militants, died in the attack.
Dog-fighting competitions are a popular form of entertainment around Afghanistan and can attract hundreds of spectators. The activity was banned during the Taliban rule.