Smoke billows from the site of an explosion in Tianjin, August 13, 2015. [Photo/CFP]

Supercomputer Tianhe-1 has been suspended. The National Supercomputing Center in Tianjin, several kilometers from the explosion site, has been damaged by blasts and although Tianhe-1 appeared to be operating correctly it has been manually paused due to safety concerns.

As of 11 am Thursday, the air quality remained normal in the region near the warehouse, the city's environmental bureau said.

The city immediately began to monitor the air and water quality hours after the blasts, setting 34 temporary monitoring stations for air and five for water.

So far, the water discharge port to the sea has been closed, and the water is being tested.

At 5:30 am, the concentration of toluene, widely used as an industrial feedstock and as a solvent, reached 3.7 milligrams per cubic meter in the air, higher than the national standard of 2.4 milligrams per cubic meter As of 11 am, all harmful gas indicators fell back to the normal range.