Hundreds of firefighters are struggling to contain flames after two explosions at a warehouse in Tianjin on Wednesday night, their efforts hampered by complex conditions at the site.

The Tianjin fire brigade said it has sent 1,000 firefighters and 143 fire engines to the warehouse, which contained dangerous goods. The volatility of the goods means the fire is especially unpredictable and dangerous to approach.

A firefighter told Xinhua that a dozen fire engines have driven into the site, and more firemen will enter to put out the flames and make way for search and rescue efforts.

Xinhua reporters saw at least 200 armed police officers around the warehouse.

At least 17 people were killed and more than 400 others were injured. Thirty-two people are in critical condition.

About 283 people have been treated in hospital, but those who suffered minor injuries have since left after treatment, according to the Tianjin municipal government.

Executives of Tianjin Dongjiang Port Rui Hai International Logistics Co. Ltd., owner of the warehouse, have been detained by police.

Read more in Special Coverage: