Afghan officials say a suicide bomber has killed at least 50 people and injured about 60 others at a volleyball tournament in the country’s eastern province of Paktika.
Mokhlis Afghan, a spokesman for the provincial governor, said the attack happened during an inter-district tournament attended by a large crowd in the Yahyakhail district late in the afternoon on November 23.
The attacker walked into a crowd of spectators and detonated his explosive vest while the match was still going on.
Most of the casualties were civilians.
Afghan said: "There were too many people gathered in one place to watch the game. Dozens of others are wounded, and we have reports that many of them are in critical condition."
He also said urgent help was needed from the central government to transfer the critically injured to hospitals in Kabul for treatment.
Correpondents report that some government helicopters were transporting injured victims to Kabul in the early morning hours of November 24.
Paktika is a volatile province where the Taliban has a strong presence.
It also borders Pakistan's tribal region of North Waziristan, where other militants groups with ties to the Taliban and foreign fighters linked to Al-Qaeda are based.
Davood Tapand, a correspondent for RFE/RL's Radio Free Afghanistan in the region, said many police officers and other officials were among the spectators.
International Olympic Committee (IOC) President Thomas Bach condemned the bombing, calling it "an attack on sport itself" and on the positive values sports can bring "to help build strong communities and foster peace and reconciliation."
There were no immediate claims of responsibility for the attack, one of the deadliest assaults in Afghanistan this year.
The Taliban and other militants have launched waves of suicide attacks and assassinations this year as foreign governments continue to withdraw most of their combat troops after 13 years of war.
The attack in Paktika came as Afghanistan's parliament approved bilateral security agreements with the United States and separately with NATO that allow international troops to remain in Afghanistan after most foreign combat troops withdraw by the end of 2014.
The new Afghan government signed the two agreements on September 30.
The agreements ratified by parliament allow the United States and NATO to keep some 12,000 troops in Afghanistan during 2015 to support Afghan forces.
The agreements came after administration officials say U.S. President Barack Obama approved new guidelines that would allow U.S. troops to continue some combat operations against Taliban fighters, not only Al-Qaeda terrorists, during 2015 as well providing U.S. air support to Afghan security forces.