The Latest: Toll from Afghanistan bombing rises to 31 dead

People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
An Afghan man walks outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
Blood-stained National ID papers and voters' photos are seen on the ground outside a voter registration center, after a suicide attack in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)

The Latest: Toll from Afghanistan bombing rises to 31 dead

People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
An Afghan man walks outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
People gather outside a voter registration center, which was attacked by a suicide bomber in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)
Blood-stained National ID papers and voters' photos are seen on the ground outside a voter registration center, after a suicide attack in Kabul, Sunday, April 22, 2018. (AP Photo/ Rahmat Gul)