A storage tank blast killed seven people and injured 24 at a plant of Indian specialty chemicals maker Aether Industries in the western port city of Surat, the company confirmed on Thursday.

The cause of the explosion early on Wednesday has yet to be determined, said city fire official Omprakash Mishra, although a fire it started had been put out. The 24 injured workers were being treated in hospital, he said.

Shares of Aether Industries fell as much as 6.2% on Thursday, after news of the blast drove them down 8.4% the previous day.

"All regulatory and government compensation to the families of all deceased shall be completed expeditiously and fully," Aether Industries said in a statement.

It promised to give additional compensation of five million rupees ($59,984) to the families of the deceased.

The company will also cover the medical expenses of the injured workers and give 2.5 million rupees per person "in case of any permanent disability".

Aether will shut the affected plant in Surat "for a few days to cater to structural audit, forensics (and) survey", a source told Reuters on condition of anonymity.

J R Chaudhari, a police officer based near the site of the blast in Gujarat state, had earlier told Reuters that seven bodies were retrieved from the factory, adding that authorities were now calling off a search for missing workers.


($1 = 83.3560 Indian rupees) (Reporting by Sumit Khanna in Ahmedabad and Nishit Navin in Bengaluru; writing by Chris Thomas and Kashish Tandon; Editing by Dhanya Skariachan and Emelia Sithole-Matarise)