BEIJING >> A huge explosion rocked a chemical plant in China ‘s eastern Shandong province around noon Tuesday, killing at least five people and injuring 19, according to local emergency management authorities. Six people were missing.

It was not immediately clear what caused the explosion.

The blast was powerful enough to knock out windows at a warehouse more than two miles away, according to a video shared by a resident, who declined to give his name out of concern about retaliation.

The resident said his home shook. As he went to the window, he saw a column of smoke from the site more than 4.3 miles away.

Gaomi Youdao Chemical Co. is in an industrial park in the city of Weifang. It manufactures pesticides as well as chemicals for medical use, and has more than 500 employees, according to corporate registration records.

Local fire officials sent more than 230 personnel to the scene, according to state broadcaster China Central Television.