The flood was caused late Tuesday by construction at EvrazHolding’s Osinnikovskaya operation.
There were 143 workers underground at the time and 139 of them were rescued.
Three had minor injuries.
It is not known if the four still trapped are injured, RIA Novosti and UPI said.
Kemerovo governor Aman Tuleyev told UPI that it had set a three-day deadline for operators to perform safety checks following the incident.
Osinnikovskaya, operated by Evraz’s Yuzkuzbasugol, is one of the oldest coal companies in the Russian region and the Kuzbass coal basin.
