Thirty-nine of the missing were firefighters who had been called to the scene of the blasts in the northern port city of Tianjin, the official Xinhua news agency reported.

New fires broke out on Friday in and around the blast site, which is scattered with chemicals and flammable substances including the highly toxic sodium cyanide, Xinhua said.

Out of the confirmed dead, 65 were reported to be firefighters and seven were police officers.

About 700 people were hospitalised by the multiple explosions that shot into the sky above the city late Wednesday last week.

The warehouse, operated by Ruihai International Logistics Company, was storing about 40 substances including 500 tons of flammable materials and 700 tons of highly toxic substances, mainly sodium cyanide, Xinhua said.

Water near the blast site was measured to contain cyanide levels up to 356 times higher than safe levels, the Environmental Protection Ministry said on Thursday.

About 4 460 soldiers and police officers are working to remove the dangerous chemicals and clean the area.

DPA