At least 18 people were killed, 65 injured and more than 50 went missing after explosions inside an oil tanker being broken up for scrap at the Gadani ship-breaking yard in the southwestern province of Balochistan, some 50 kilometres (30 miles) west of Karachi.
“A gas cylinder explosion caused a huge fire in the ship which was being dismantled,” Balochistan home secretary Akbar Harifal told a foreign media agency, ruling out a deliberate attack.
“All the injured had severe burns,” he added.
Local government official Zulfiqar Hashmi told a foreign media agency 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.
Prime Minister Nawaz Sharif expressed his “deep grief and sorrow” over the incident, according to a statement by his office.
Industrial accidents are common in Pakistan, with workplaces often forgoing basic safety measures and equipment in the absence of legislation to protect labourers.
A devastating fire at a textile factory in Karachi killed 255 people in 2012.
