Shanghai: Chinese authorities warned that cyanide levels in the waters around the Tianjin Port explosion site had risen to as much as 277 times acceptable levels although they declared that the city's drinking water was safe.

The local government also said it would relocate chemical plants away from the area, where thousands of nearby residents were forced to evacuate after toxic chemicals were detected in the air due to the explosions last week, which killed 114 people.

A report from the Tianjin Environmental Protection Bureau issued on Wednesday said that tests conducted the day before showed cyanide levels in the river, sea and waste water in the evacuated area surrounding the explosion site had risen sharply since the deadly blasts. One testing site at the mouth of a rain water pipe recorded cyanide levels 277 times above acceptable standards.