NATO Secretary General Jens Stoltenberg has strongly condemned Sunday’s suicide attack in Afghanistan’s capital Kabul which killed at least 31 people and wounded more than 50 others at an ID distribution center in the western part of the nation’s capital.

Daesh militant group claimed responsibility for Sunday’s deadly attack.  

Stoltenberg said the alliance will continue backing the Afghan people in the fight against terrorism.

“I strongly condemn the attack on a voter registration center in Kabul. #NATO stands with #Afghanistan in the fight against terrorism and for democracy,” Stoltenberg tweeted.

UNAMA also condemned the attack.

In a tweet, the mission said: “UN in #Afghanistan outraged by today’s attack in #Kabul. Reports indicate more than 30 civilians killed, many hurt, in latest apparent deliberate targeting of election-related facilities. UN supports Afghans constitutional right to participate in elections free of intimidation.”

Meanwhile, Afghan political leaders and members of the Meshrano Jirga (Upper House of Parliament) have also denounced the attack and said it was a crime and act of terrorism.

Afghanistan’s CEO also spoke out and tweeted: “I strongly condemn the terrorist attack on voters' registration center in Kabul. I stand with those affected by this coward attack. Our resolve for fair and transparent elections will continue and terrorists won't win against the will of the Afghan people.”

Afghan senators also slammed the attack and said it was a crime against humanity.

Senators also blasted Afghan security forces and security institutions for not being able to thwart such attacks in the city.

The senate also decided to summon the minister of interior, Wais Ahmad Barmak, to respond to questions over the rising security concerns and the security arrangements around elections.

By Sunday mid-day, there had been five attacks in less than a week against the election process.

Two hours after the Kabul bombing, an explosion rocked Pul-e-Khumri city in Baghlan province, killing at least six people and wounding five others.

This explosion happened close to a voter registration center in the provincial capital, officials confirmed.

Last week three other attacks took place.

On Tuesday, 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.

On Thursday, unknown armed men attacked two police force members in Jalalabad City who were guarding a voter registration center.

The two policemen were killed in the ensuing gunfight.

On Friday, unknown armed men attacked a voter registration center in Qala-e-Naw, the center of Badghis province, where a police officer assigned to maintain security was killed.