A suicide bomber detonated explosives during a volleyball match in eastern Afghanistan on Sunday afternoon, killing at least 45 people and leaving 80 others wounded, said Mokhlis Afghan, a spokesman for the provincial government. For now, no one has claimed responsibility for the attack, and the Taliban's spokesman could not be reached.

The attack, which occurred amongst a crowd in the Yahyakhil district of Afghanistan's southeastern Paktika province,  was launched hours after the nation's Parliament approved security agreements allowing 12,000 U.S. and NATO troops to remain in Afghanistan past the end of the year, the Associated Press reported.

The suspect, who was on foot and mingling with the crowd, was within the midst of spectators when the bomb exploded during an inter-district volleyball tournament after 5 p.m., leaving dozens wounded and in critical condition.

"There were too many people gathered in the one place to watch the game. Dozens of others are wounded and we have reports that many of them are in critical condition," Afghan said. "We need urgent help from the central government because we might need to transfer wounded people to Kabul for treatment," he added.

Apart from civilians, the dead victims also included eight members of the Afghan Local Police, a village-based paramilitary outfit that supports the Afghan government, Bahawul Khan Katawazai, a member of the provincial council in Paktika, said.

Paktika, bordering Pakistan, is one of Afghanistan's most volatile regions, where a Taliban-led insurgency and affiliated insurgent groups such as the Haqqani network, which regularly sends young men on suicide attacks against high-profile targets, are waging an intensifying war against the government in Kabul, according to CNN.

Sunday's attack also coincides alongside contentious election and the inauguration of President Ashraf Ghani in September, whose first act after being elected was to sign the agreements, which are bitterly opposed by the Taliban and other insurgent groups.

Meanwhile, as President Obama's presidency draws to an end, he wants all U.S. troops to be out of Afghanistan by the end of 2016, The Boston Globe reported.

Similarly in 2010, a suicide car bomb exploded in the middle of a group of men playing volleyball, a popular sport in the region, in northwest Pakistan. That attack left 30 people dead and 52 wounded.

The Taliban had banned sports such as boxing and soccer when the group governed Afghanistan from 1996 to 2001. In the years since, even as suicide attacks by various insurgent groups, including the Taliban, have become more frequent, sporting events have rarely been targets.

So far this year, there have been at least five suicide attacks in Paktika province; many of the suicide bombers who carry out attacks in Afghanistan are trained in nearby Pakistan.