KABUL — Afghans joined in anger and sorrow Thursday amid gutted buildings and piles of rubble in bomb-ravaged Kabul, as mourners buried the dead and officials grappled with questions over how to confront a seemingly unstoppable insurgent threat.

Wednesday’s truck bombing in the Afghan capital’s diplomatic zone — one of its most highly guarded areas — claimed more than 80 lives, injured another 460 people and devastated entire blocks in one of the bloodiest single attacks to hit Afghanistan in years.

Afghan Taliban insurgents denied any links to the explosion, which came during the first week in the Islamic holy month of Ramadan. But Afghanistan also faces violence from other militant groups, including a branch of the Islamic State.

Crews with bulldozers and backhoes worked to clear away building debris and wrecked cars in a large area around the 15-foot-deep bomb crater, sealed off by hundreds of police.

Victims’ families began holding funerals and mourning ceremonies in mosques across the city. Relatives of those with severe injuries — including extreme blast burns — hovered worriedly around their hospital beds.