Vadodara, Nov 3 (PTI): Four workers were killed and 13 sustained injuries in a gas leakage at the TDI unit of Gujarat Narmada Valley Fertilizers and Chemicals Ltd (GNFC) in Dahej in neighbouring Bharuch district, police said today.

Four workers were killed and as many as 13 others were injured due to leakage of phosgene gas at the TDI unit last night, Bharuch Superintendent of Police, Sandeep Singh told PTI.

Prima facie, it looks the mishap took place due to mechanical failure, he said.

The 13 injured were admitted to a hospital in the district, out of which two have been referred to government hospital in Baroda. Three workers were discharged, Singh said.

A team of Forensic Science Laboratory will visit the site later in the day, he added.

Meanwhile, district Collector Sandeep Kumar Sagale said, "We have asked Director of Industrial Safety and Health to investigate the mishap. The management of GNFC has also appointed a technical committee to probe the matter."