Seventeen people, among them a woman, were killed and 33 others wounded when a mine went off inside an election-related facility in Khost province, Khost police chief Abdul Mannan confirmed on Sunday.
The IED reportedly was placed inside a mosque which was a facility center for registering voters.
So far no group including Taliban has claimed responsibility for the explosion.
Meanwhile, President Ghani, in a statement condemned the Khost explosion and said enemies cannot disturb the national election process. He ordered security institutions to investigate and bring the perpetrators to justice.
Ghani also expressed his condolences to the victim’s families, the presidential palace statement said.
"I strongly condemn the terrorist attack in a Masjid in Khost this afternoon. Attacking worshippers and holy sites is against all human and religious values. Terrorists yet again committed a war crime by targeting Muslim civilians in Masjid," said Chief Executive Officer Abdullah Abdullah.
US embassy in Kabul also condemend the attack.
"I condemn the savage attack at a voter registration center at a #Khost mosque and offer my condolences to the victims and their families. This is an affront to the democratic values of the #Afghan people and an attack on the concept of citizenship," said US ambassador to Kabul John Bass.
Since April 14, the start of the voter registration process, seven attacks have been carried out at election-related facilities across the country.
At least 60 people were killed and 129 others were wounded in a suicide bombing in Kabul at a population registration center about two weeks ago.
Just hours after the Kabul attack, five people were killed and six others wounded in Pul-e-Khumri city in Baghlan province after an IED was detonated at a registration center.
On Friday, April 20, unknown armed men attacked a voter registration center in Qala-e-Naw, the center of Badghi's province, where a police officer assigned to maintain security was killed.
On Thursday, April 19, unidentified armed men attacked two police force members in Jalalabad City who were guarding a voter registration center. The two were killed in the ensuing gunfight.
On Tuesday April 17, unknown armed men attacked a voter registration center in Ghor province and kidnapped three IEC employees and two policemen. Ghor police spokesman said the attackers were Taliban.