A day after authorities declared the city's drinking water safe, the state media reported thousands of dead fish appeared on the shore of the Tianjin river. Tianjin officials blamed regular seasonal low oxygen levels for the dead fish. (Reuters)

Not long after it was announced that cyanide levels have exceeding national standards at the site of China’s deadly explosion in Tianjin, thousands of dead fish washed ashore at the nearby Haihe River prompting even more concern over the environmental consequences of the blast.

Photos published Thursday by Chinese state media showing thousands of the dead fish seen washing up four miles from the Tianjin blast site quickly went viral, according to the Wall Street Journal. “‘If the dead fish are related to the explosion, then this is a regional disaster,’ one user wrote on Weibo, ‘The culprits must be sentenced to death’” the Journal reported.

The Tianjin municipal government said the fish had been examined and and no cyanide compounds had been detected.

Deng Xiaowen, who is head of Tianjin’s environment monitoring center, said during a press conference on Thursday that it’s not uncommon for fish to die in the summer due to poor water quality. Cao Shuxiang, from the fisheries bureau in Tanggu district told Xinhua “it’s not rare to see dead fish offshore in summertime due to a lack of oxygen in the water caused by excessive nutrients.”

But local residents had their doubts.

“I’ve never seen anything like it,” Wang Lei, 47, a freight company manager told the New York Times as he looked at mass of dead fish on the shore of the river “There has to be a link between the dead fish and the blast. What else could explain the death of so many?”

Dead fish float along the shore of Haihe River Dam on August 20, 2015 in Tianjin, China. (ChinaFotoPress/ChinaFotoPress via Getty Images)

More than a week after the deadly blasts and raging fire that claimed at least 114 lives, workers are still cleaning up the more than 2,500 tons of hazardous chemicals stored at the warehouse including 700 tons of potentially deadly sodium cyanide, the New York Times reports.

According to the state media, technicians have detected as much as 356 times the national safe level of cyanide within the evacuated area of the blast site and officials have assured the public that “most water outside the zone meets national safety standards,” Xinhua, the state-run news agency reported. Xinhua also reported that the government has set up 42 water quality monitoring stations, including 19 that detected sodium cyanide with the cordoned-off area.

Workers remove dead fish from the Haihe river at Binhai new district in Tianjin, China on August 20, 2015. (Reuters)