
The comments by Shi Luze, chief of the general staff of the Beijing military region, were the first official confirmation of the presence of the chemical at the hazardous goods storage facility at the centre of the blast.
The disaster has raised fears of toxic contamination and residents and victims' families hit out at authorities for what they said was an information blackout, as China suspended or shut down dozens of websites for spreading "rumours".
Nearly 100 people remain missing, including 85 firefighters, though officials cautioned that some of them could be among the 88 unidentified corpses so far found.
More than 700 people have also been hospitalised as a result of Wednesday's blasts -- which triggered a huge fireball and a blaze that emergency workers have struggled to put out since then, with fresh explosions on Saturday.
Shi, who is a general, told a news conference that cyanide had been identified at two locations in the blast zone. "The volume was about several hundreds of tonnes according to preliminary estimates," he said.
A military team of 217 chemical and nuclear experts was deployed early on, and earlier Chinese reports said 700 tonnes of sodium cyanide were at the site.
Officials have called in experts from producers of the material -- exposure to which the US Centers for Disease Control says can be "rapidly fatal" -- to help handle it, and the neutralising agent hydrogen peroxide has been used. ?AFP