Search and rescue work has ended at the site of a fireworks explosion where nine were killed and another nine injured Friday in central China 's Hunan Province, said local authorities.

The blast occurred in Ningxiang County, in Changsha, the provincial capital, at about 9:30 p.m. Friday when a truck loaded with fireworks fuses hit a power pole and sparks from fallen cables ignited the fuses.

The blast destroyed the truck and nearby houses, and shattered windows and cracked walls hundreds of meters away.

Rescuers found no life signs under the ruins while using dogs searching for victims as well as life detector equipment, so the focus shifted on Saturday at noon from finding survivors to site clean-up and investigating the cause of the explosion, said officials at the rescue headquarters.

All the injured, including two who were seriously hurt, are being treated in hospital.

The whereabouts of the truck driver remains unknown.

Residents said the blast sounded like thunder and sent a column of smoke high into the air. Rubble was blasted into nearby fields.

A fireworks plant was located near the site and the truck was loaded with 600 boxes, each holding 24 kg, of fireworks fuses, said resident Li Dehui.

Police are still investigating the cause of the accident.