Hong Kong CNN  — 

Chinese emergency workers were working to extinguish four fires Friday that broke out at the site of last week’s fatal blasts in the northern city of Tianjin, the state-run Xinhua News Agency reported.

Three of the fires were at the core of the explosion site, while a fourth was at an automobile distribution center nearby and could have been caused by a burning fuel tank, Xinhua said.

The August 12 blasts occurred at a warehouse, where more than 700 tons of highly toxic substances, mainly sodium cyanide, were being stored.

At least 116 people were killed as a result of the explosions.

The explosions affected a huge swath of the city: 17,000 homes damaged, more than 170 companies affected and 3,000 cars destroyed.