Four people have been detained in connection with a factory explosion that caused 16 deaths in east China's Anhui Province on Sunday, local authorities said on Tuesday.

The four were Cao Peijun, general manager of Jingxin Mining Co. Ltd., his son Cao Shun, deputy general manager of the company, Li Guangquan, the company's production deputy chief, and Sun Jiancheng, deputy general manager of Dengbao Mining Company, according to Wang Tuqiang, vice mayor of Chuzhou City, who is in charge of the investigation.

They were detained for illegally storing explosives.

An estimated five to seven tonnes of explosives stored in the two-storey office building of the Jingxin Mining Co. Ltd. in Fengyang County of Chuzhou, detonated at 3:17 AM on Sunday, killing16 people and injuring 43 others.

The blast left a 5-meter-deep pit, which was 10 meters in diameter, razed the two-storey building and ripped through nearby workers' dormitories, dining halls and workshops.

Most of the victims were workers, who were struck by debris as they slept. Many of the injured were residents hit by broken glass or debris.

Jingxin is a privately-owned company that processes about 30,000tonnes of quartz sand annually. Its products are sold domestically and exported to Southeast Asia and Europe. The firm has about 60 employees and started production in 2003, registering 20 million yuan in fixed assets.

Jingxin has no mining business, and thus has no need for explosives. It didn't obtain permits for using or storing explosives, said investigators.

During interrogation, Jingxin managers confessed they bought explosives with a license borrowed from Dengbao Mining Company, a legal explosive user, and stored the explosives at the office building.

Fan Dijun, head of the Fengyang county government, confirmed Tuesday families of the dead would each receive compensation of 300,000 yuan (US$44,000), instead of 250,000 yuan as reported on Monday.

Eleven remains were cremated as of Tuesday, according to Chuzhou Vice Mayor Wang Tuqiang.

(Xinhua News Agency June 24, 2009)