Officials in China are grappling with the mysterious appearance of thousands of dead fish that washed ashore Wednesday, just four miles from the deadly Tianjin blast site that killed more than 100 people, according to The New York Times.

There have been suspicions that the wastewater runoff near the site has sodium cyanide in it, a deadly chemical that can kill people in even the smallest doses.

A warehouse that stored 2,500 tons of toxic chemicals was involved in the blasts, but Chinese officials are denying that the blast and the large scale fish death are connected at all, according to The Huffington Post.

"It was not uncommon for fish to die en masse in local rivers during summer, due to poor water quality," said Deng Xiaowen, head of Tianjin's environment monitoring center.

Residents are not as convinced that the fish are a regular occurrence, with some saying that they've "never seen anything like it" and questioning what else could cause such a large scale death of aquatic life.

Technicians have found up to 356 times the national "safe" level of cyanide within the evacuated area of the blast site, The Washington Post reported.

News agencies report that the government has set up 42 water quality monitoring stations for public safety, with 19 of them having detected cyanide.