A bomb blast tore through a crowd gathered to watch dog fighting in the southern Afghan city of Kandahar on Sunday, killing dozens of people, witnesses and an official said.
An AFP reporter at the scene said he had counted around 25 bodies but officials could not immediately provide a figure.
"Tens of people have been killed and tens have been wounded," interior ministry spokesman Zemarai Bashary told AFP.
"It was a bombing but at this point we don't know if it was a suicide bombing or other bombing."
Dozens of bloodied boots and clothes lay among dead bodies and limbs, the reporter said. Police reinforcements rushed to the scene as civilian and police cars and ambulances ferried the wounded to hospitals, the reporter said.
At least one big fighting dog was also killed, he said.
Witnesses said the blast appeared to have been a suicide bombing of the sort carried out by insurgents from the extremist Taliban movement.
A witness, Ahmad Khan, said "dozens" were killed.
"Hundreds of people had gathered and the dog fighting was under way when the explosion took place. It was a suicide bombing," he told AFP.
The Taliban were in government between 1996 and 2001 and last year carried out around 140 suicide attacks across Afghanistan.
The extremist religious movement rose from Kandahar province in the early 1990s. Kandahar city had seen a wave of suicide blasts and other attacks but these tailed off last year. (AFP)
Bomb at Afghan dog fighting kills dozens