Industries Secretary Abdun Naser Khan said on Saturday that toxic hydrogen sulphide gas caused the deaths of nine workers on Friday at the Sitakunda shipbreaking accident, after the explosives department found the gas at levels higher than normal.

The Department of Explosives found elevated levels of the gas aboard the vessel at Ferdous Ship Recycling Industries in Bhatiari, Sitakunda, the industries secretary told journalists after visiting the yard.

He was accompanied by Chattogram district administrator Mohammad Zahidul Islam Mia, police superintendent Masud Alam and explosives inspector SM Sakhawat Hosain, among others.

Khan said three separate investigation committees had been formed into the accident: an 11-member panel headed by an additional secretary from the industries ministry, a nine-member committee from the district administration and a five-member committee from the Bangladesh Ship Recycling Board (BSRB).

The committees have been asked to examine what happened before and after the incident and to determine whether there was negligence or dereliction of duty, Khan said. They have been told to submit their reports quickly.

The secretary said action would be taken if investigators found negligence. The accumulated toxic gas would be removed safely by specialists and maximum precautions would be taken to prevent similar deaths in future.