Beijing, Aug 18 (IANS): Thousands of tonnes of contaminated water at China's Tianjin port -- the site of two massive warehouse explosions on August 12, needs to be treated over fears that rain may exacerbate the problem.

Pipeline and ground water at the blast site will be processed and drained to make room for the coming rain, Xinhua quoted Bao Jingling, chief engineer of Tianjin bureau of environmental protection as saying on Tuesday.

On Monday, water tested at eight of the 40 water monitoring stations in the area was found to contain excessive cyanide, with some samples containing 28.4 times more than the standard, according to Bao.

Bao made the remarks as the city witnessed a light-rain shower on Tuesday, stoking fears that rescue efforts would be disturbed and contamination would spread at the site where hundreds of tonnes of toxic cyanide were stored.

Air quality is being monitored as rain might set off reactions with the scattered chemicals and release toxic gases.

The environmental authority may establish more monitoring stations, Bao said, adding that monitoring personnel from other cities and provinces have been despatched to Tianjin.

A total of 114 people have been confirmed dead, and 57 remain missing after two huge explosions on August 12 at a warehouse that held hazardous chemicals.

Officials say that around 700 tonnes of sodium cyanide stored at the blast site remains mostly unaffected.

As of Monday chemical specialists had searched a radius of three km around the blast site's core area. "We have cleaned 150 to 160 tonnes of sodium cyanide," said He Shushan, vice mayor of Tianjin.