Seven workers suffocated to death in Andhra Pradesh’s Kakinada district on Thursday while cleaning a tanker in an oil factory, The Times of India reported.

The incident took place in the Ambati Subbanna oil factory in the Peddapuram mandal. Those who died have been identified as Vechangi Krishna, Vechangi Narasimham, Vechangi Sagar, Korathadu Banji Babu, Karri Rama Rao, Kattamuri Jagadeesh and Prasad.

They suffocated to death after they entered a 24-feet-deep oil tanker to clean it, according to IANS.

Kakinada District Collector Krithika Shukla told reporters that the factory has been sealed and a case has been filed under Section 304A (death due to negligence) of the Indian Penal Code, PTI reported.

A four-member committee headed by the joint collector has been formed to submit a report within three days on whether the factory authorities were guilty of negligence, Shukla said. The committee members are looking into the documents of the approval obtained to run the factory.

The state government has announced a compensation of Rs 25 lakh for the families of the victims.

The families of those who died have alleged that the factory management did not take adequate safety precautions. Superintendent of Police M Ravindranath Babu said that criminal action will be taken against the management of the factory.

Peddapuram MLA Chinnarajappa visited the oil factory and claimed that inexperienced workers were hired to clean the tanker, IANS reported.