BEIJING (AP) — The port city of Tianjin in northern China was rocked by a warehouse blast, police said Tuesday, two months after massive explosions in the city left 173 people dead or missing.

The blast hit a warehouse for alcohol materials in the city Monday night and started a fire, but no casualties were reported, local police said.

Tianjin had been ordered after the August blasts to perform thorough checks to eliminate workplace hazards, with a special focus on warehouses storing chemicals. The new blast underlines the challenges that China faces in ensuring workplace safety.

Tianjin police said they detained the owner of a chemical company that illegally rented a private warehouse from an area resident to store chemicals. The resident, identified by his family name, Huo, was also detained, police said.

Local authorities said 3,000 kilograms (6,600 pounds) of alcohol were being stored in the 700-square meter (7,500-square foot) warehouse, along with 1,000 kilograms (2,200 pounds) of acetic acid, which can be used in the making of plastics and pharmaceuticals.

The local government said the explosion posed no risk to people or the environment.

In August, a warehouse complex storing large amounts of hazardous chemicals caught fire and exploded in Tianjin, killing 165 and leaving eight missing.

The disaster raised questions about corruption and government efficiency. Investigations into the Aug. 12 blasts at the Ruihai International Logistics warehouses showed they were located closer to homes than permitted, and stored much more hazardous material than authorized, including 700 tons of highly toxic sodium cyanide.