At least five people were confirmed dead after a blast at a chemical plant on midnight Monday in East China's Shandong Province, said local authorities in wee hours of Wednesday.

The explosion occurred at around 11:22 p.m. Monday at Shandong Binyuan Chemical Co., Ltd. in Diaokou Township of Lijin County, according to the publicity department of Dongying City, which administers Lijin.

Fire was put out at around 4: 20 a.m. Tuesday, and waste water from the plant has been sealed without any spillover, the publicity department said. Air quality at the site is being monitored, which was "up to standard" till 8:00 a.m. Tuesday, the authorities added.

Cause of the incident is under investigation.

According to the website of Shandong Binyuan Chemical Co., Ltd., the company is a wholly-owned subsidiary of Shandong Binyuan Group. It was founded in March 2014 and is located in Binhai Economic and Technological Development Zone of Lijin County. The company is a high-tech enterprise with an annual production capacity of 20,000 tons of modified adhesive materials.