A suicide bomber killed more than 50 people in a rural province of Afghanistan near the Pakistani border during a volleyball tournament. The assailants targeted the crowded sporting event for maximum casualties despite the fact that no tribal elders or government officials were present.

The attack took place in the Yahya Khel district of Paktika Province on Sunday, according to the New York Times. The majority of the victims were civilians, who had congregated for a volleyball tournament between the province's three districts. Volleyball is a very popular sport in Afghanistan.

The blast happened at around 5 p.m. in a small village in the district. Among those wounded were members of the Afghan Local Police, a paramilitary group that supports the government.

According to Mokhlis Afghan, spokesman for the governor of Paktika province, the bomber began mingling with spectators before detonating the explosives, reports the Associated Press.

Though no group has claimed organization, it is believed the Haqqani network, which tends to target high-profile events and gatherings, conducted the attack. The Taliban has shied away from targeting gatherings with women and children because they cause increased outrage.

Government officials said there were no specific individuals that could be targeted at the event, reports AFP. The death toll, which had numbered around 50 Sunday, rose to 57 on Monday after some of the injured died from their wounds.

Survivors were taken to a military hospital in Kabul via helicopter where they are receiving treatment. Some of the victims explained what happened.

"The game was about to end when we heard a big bang," Salaam Khan, 19, told AFP."I was shouting for help. Just beside me was a dead army officer."

"There were local police and commanders watching the game. I saw some killed and wounded," he added.

Other survivors and witnesses described a chaotic scene as people clutched their injuries and family looked for their relatives among the frightened crowd.

President Ghani, who was elected earlier this year, visited the hospital and spoke with victims. He called the attack "inhumane and un-Islamic."

The U.N. Assistance Mission in Afghanistan condemned the attack, calling it an "atrocity" and it "demonstrates a complete disregard for civilian life."