Islamabad, Nov 2 (IANS): The death toll in a series of explosions during the cleaning of an unused oil tanker at the Balochistan port in Pakistan on Wednesday mounted to 18 as more bodies were recovered from the site, officials said.

More than 50 labourers were also injured on Tuesday after a series of blasts ripped through an oil tanker at the ship-breaking yard, according to local officials. Many were reported trapped inside the vessel, Geo News reported.

Nasir Mansoor, a representative of the National Trade Union Federation of Pakistan, said the explosion sent pieces of metal flying up to 2 km away.

The blast occurred in the fuel tank of the ship, which was still on fire, he said.

Firefighters from Karachi and from the air force and navy were attempting to put out the blaze, he said.

Mansoor said the firefighters would have to wait for the fire to die out "as they lack the foam required douse it".

Labourers in Gaddani, which is 45 km from the port city of Karachi, often work in poor conditions without basic protective gear, the report said.

Prime Minister Nawaz Sharif expressed his condolences to the families of those who lost their lives in the explosion and has ordered an inquiry into the accident.