KARACHI - At least 16 workers were killed and more than 50 injured on Tuesday after a huge blast ripped through an oil tanker being broken for scrap at Gadani, trapping several others inside the vessel.

Scores of workers were working at the ship breaking yard when the fire broke out following a gas cylinder blast.

“A gas cylinder explosion caused a huge fire in the ship which was being dismantled,” Balochistan Home Secretary Akbar Harifal told AFP, ruling out a deliberate attack.

“We have recovered at least 16 bodies so far and shifted 55 injured to Karachi,” Zulfiqar Ali Shah, the deputy commissioner of the area, told AFP. “All the injured had severe burns,” he added.

Local government official Zulfiqar Hashmi told AFP the ship was still ablaze and there was not enough equipment to extinguish it. Both he and Shah said Pakistan Navy firefighters had been called in to help.

TV footage showed a thick plume of black smoke rising from the ship as local rescue workers rushed to the scene.

Hospital sources confirmed the death of 16 people while wounded, some of them with serious burn injuries, were shifted to Jinnah Postgraduate Medical Centre (JPMC).

Witnesses said over 100 people were working on the ship when the blast occurred in the oil tanker. They said rescue operation was halted due to darkness and will resume in the morning. The burnt bodies of the victims were beyond recognition and were shifted to the morgue.

Provincial Disaster Management Authority and the National Disaster Management Authority along with rescue teams of Navy, fire brigade department and other welfare organisations participated in the rescue operation.

The leader of a ship-breaking workers union said fire had engulfed the vessel moored in Gadani, 45km northwest of Karachi. “Things are really bad here,” union president Basheer Mehmoodani told Reuters by telephone. “There’s an unclear number of workers said to be trapped in the burning ship.”

Nasir Mansoor, a representative of the National Trade Union Federation of Pakistan, said the explosion sent pieces of metal flying up to two kilometres away. Mansoor said the firefighters would have to wait for the fire to die out “as they lack the foam required to douse it.”

Staff Reporter from Quetta adds: Taking notice of the fire incident, Balochistan Chief Minister Nawab Sanaullah Khan Zehri directed the deputy commissioner Lasbella to present a report on the tragic incident within 24 hours.

Zehri ordered immediate halt to the all ship breaking work at Gadani’s yard. He also ordered cancellation of the licences of those contractors violating the rules for ship breaking.

The chief minister announced compensation for the affected families.

Prime Minister Nawaz Sharif expressed his “deep grief and sorrow” over the incident, according to a statement issued by his office in Islamabad.

Labourers in Gadani often work in poor conditions without basic protective gear.

The Gadani ship-breaking industry has fallen on hard times recently and employs about 9,000 workers, fewer than in its boom years at the end of the last decade.