The blast occurred shortly before 8:30 am Monday at a factory in a village outside Changde, a city in Hunan province, state-run China National Radio (CNR) said.

As of 9:00 am on Tuesday, nine people were dead and 26 injured, CNR said citing a rescue command centre.

Rescue work at the scene was ongoing, CNR reported, noting a "complicated" situation and the risk of additional explosions hampering response efforts.

Adding to the challenge, the site was in a "mountainous area with no large water source", it added.

"During more than 20 hours of uninterrupted and continuous rescue, the rescue team used remote-controlled water cannons to extinguish the fire," the report said.

State news agency Xinhua also said Tuesday that the Ministry of Emergency Management had sent a working team to Hunan to oversee the rescue.

"Efforts must be made to ascertain the cause of the explosion as soon as possible and to hold those responsible accountable," the ministry said, according to Xinhua.

Industrial accidents are fairly common in China due to vague regulations and lax safety standards.

Last month, an explosion at a chemical plant in the eastern province of Shandong killed at least five people.

In 2015, blasts at warehouses containing flammable chemicals in the port city of Tianjin killed more than 170 people and injured 700 others.