At least four workers were killed and nine others injured today in a blast at a chemical plant of GSP Crop Science Pvt Ltd. The blast led to a huge fire at the premises, a police official said.

The blast occurred at around 5.30 am. The chemical plant is located at the Gujarat Industrial Development Corporation (GIDC) area at Nandesari near here.

“Four of the firm’s employees were killed in the blast,” Vadodara district collector P Bharthi said.

The injured persons were admitted to different hospitals, she said, adding that two of the injured were reported to be serious. “We have ordered an inquiry into the blast,” she said.

The cause for the blast was not immediately known. The fire-fighters took around two hours to douse the blaze, a police official said.

Machinery and equipment at two plants of the company were damaged in the incident. The company's units located in the surrounding areas were asked to shut down, a fire brigade official said.