BEIJING (AP) — An explosion at a fireworks plant in a central Chineseprovince killed at least 26 people and injured 61 others, authorities reported Tuesday.

China’s official news agency Xinhua said the blast occurred at a fireworks plant in Changsha city of Hunan province on Monday afternoon. State media China Daily said the plant was operated by the Huasheng Fireworks Manufacturing and Display Co. in the Changsha-administered, county-level city of Liuyang, a prominent fireworks powerhouse.

Changsha mayor Chen Bozhang said search and rescue at the scene has largely been completed, but verification of the casualties and identification of the victims are still underway.

Aerial footage from state broadcaster CCTV on Tuesday showed white smoke still billowing in certain areas of the site, with facilities collapsed or damaged.

Nearly 500 rescuers were deployed to the scene and residents in danger zones were evacuated by authorities, citing high risks from two black powder warehouses near the explosion site, the Xinhua report said.

Authorities were investigating the cause of the blast and police have detained the person in charge of the company, Xinhua said.

Chinese President Xi Jinping urged “all-out efforts” to search for people who are still unaccounted for and save the injured. He called on authorities to investigate the cause swiftly and pursue serious accountability, the report said. Xi also ordered effective risk screening and hazard control in key industries and the strengthening of public safety management.

To prevent other accidents during the operation, rescuers adopted measures such as spraying and humidification to eliminate potential hazards.

They also deployed three robots to help with the search and rescue operation.

Liuyang has a long history of fireworks production. The Guinness World Records organization said the first accurately documented firework, the Chinese firecracker, was attributed to Li Tian, a monk who lived near Liuyang during China’s Tang dynasty dating to around 618 to 907 C.E. Li discovered that putting gunpowder in enclosed hollow bamboo stems created loud explosions and bound crackers together to create the traditional New Year firecrackers to drive out evil spirits, Guinness said.

In February, China reported two deadly explosions at fireworks shops around the Lunar New Year period.