Fear of chemical contamination at the blast site in Tianjin، the Chinese authorities have ordered the evacuation of residents within a 3km radius of the blast site.
The evacuations came as police confirmed the highly toxic chemical sodium cyanide was found near the site.
A man was found alive 50m from the blast core،Xinhua news agency said.
Eighty-five people are now known to have died and hundreds were hurt in the giant blasts in the north-eastern Chinese port on Wednesday.
An oral dosage as small as 200-300 mg of NaCN can be fatal، scientists say.