Ji Mi / Shanghai Daily news

The death toll in the Hebei Province coal mine gas blast rose to 87 yesterday, the rescue headquarters said. Another 21 were still missing.

Meanwhile, police detained the owner of the private colliery and an unspecified number of mine executives, media reported yesterday. The mine owner was not identified.

Authorities also confiscated work logs and other mine documents and froze the business' account while further investigation was underway.

A gas explosion rocked the Liuguantun Coal Mine in Kaiping District, Tangshan City, at about 3:15pm on Wednesday.

Colliery managers initially reported that 82 miners got out safely shortly after the blast, and 104 were trapped underground, a figure that was later raised to 108.

As of late yesterday, more than 150 rescuers were trying to reach the 21 missing miners.

The rescue work has been hampered by carbon monoxide 100 times above safety standards.

The families of the miners killed receive 220,000 yuan (US$27,241) each.