© Stringer / Reuters
Damaged vehicles are seen as smoke rises from shipping containers after explosions at Binhai new district in Tianjin, China, August 13, 2015.
Chemical warfare units deployed to the site of explosions in Chinese port of Tianjin have detected toxic fumes in dangerous concentrations up to half a kilometer from the blasts.

Sulfur oxide, carbon monoxide and nitrogen oxide, all products of combustion, have been found in the air, Xinhua reported. Plumes of white and yellow smoke, which may be an indicator of toxic hydrogen sulfide, were seen rising over the area.

The authorities ordered evacuation from the vicinity of the affected zone, with chemical warfare units monitoring the developing situation.

The team includes 217 nuclear, biological and chemical specialists, according to Xinhua news agency. China also deployed 130 militiamen and 125 military officers and soldiers to assist with the rescue operation.

The series of explosions at a warehouse in Tianjin has claimed at least 50 lives and injured over 700. Dozens of people remain unaccounted for, including over 30 firefighters.

It is estimated to be one of the worst man-made disasters in China in years.