HARBIN - One person was killed and nearly 30 others were injured after carbon monoxide gas leaked in a steel company in Harbin, capital city of Northeast China's Heilongjiang province late Monday night, local authorities said.

The leaks happened at around 10 pm in Acheng Iron & Steel Co, Ltd. in the city's Acheng district, an official with the district government said. The injured are receiving treatment in hospitals and 10 of them are in serious conditions, he said.

Rescuers are still determining the exact number of casualties and an investigation into the cause of the accident is underway, he added.

The company, under Xilin Iron & Steel Group, is the the province's largest steel producer, according to its official website.