Reports say a powerful explosion ripped through a chemical plant in eastern China Thursday, killing at least 47 people and severely injuring 90 others.

Firefighters were still battling small fires Friday morning, after working through the night to put out the main blaze.

Drone footage from the country’s emergency management ministry shows an industrial area outside Yancheng city in Jiangsu province covered in firefighting foam, with storage tanks turned to twisted metals and charred factory buildings with roofs torn open.

Local authorities said earlier that dozens of fire trucks and hundreds of firefighters rushed to the scene after the blast was reported around 2 pm Thursday.

Reports say the explosion was powerful enough for the seismological bureau to detect a small earthquake in the area.

National broadcaster CCTV aired dramatic surveillance and cell phone videos of windows blown out in nearby buildings at the time of blast, with witnesses telling reporters the impact could be felt as far as 5 kilometers away and others saying they suffered cuts from broken glass.

Several schools are situated near the chemical plant, Tianjiayi, including a kindergarten less than a kilometre away, prompting concern and anger on Chinese social media.

State media reported the chemical that caused the explosion was benzene, a highly flammable and toxic compound classified as a carcinogen, adding that the pesticide factory failed a government safety inspection last year.

Local environmental officials, who set up monitoring devices throughout the industrial park and nearby areas after the blast, said heavy wind had created favourable conditions for toxic air to dissipate.

The authorities have detained “relevant personnel connected to the accident”.

President Xi Jinping, who is on a state visit to Italy, urged rescuers to keep working and ordered officials to draw immediate lessons from the accident.

In August 2015, a series of chemical explosions at a container storage facility in the norther city of Tianjin killed more than 160 people and injured almost 800 others.