MOSCOW, Feb. 13 (UPI) -- Russian investigators said Wednesday they have handed off to prosecutors the results of a six-year inquiry into one of the country's worst coal mine accidents.
An explosion at the Ulyanovskaya coal mine in western Siberia March 19, 2007, killed 110 people, RIA Novosti reported.
Investigators have determined methane explosion, one of the biggest coal accidents in Russia in 80 years, was caused by violations of safety rules.
The mine director and five other mine employees have been charged with breaches of safety rules that led to multiple deaths. Three state officials face negligence charges,
The charges carry prison terms of seven years.
Charges against 19 engineers were dropped because of the statute of limitations.
On Monday, 18 miners died from carbon monoxide poisoning and injuries after a methane blast at the Vorkutinskaya mine in the Komi republic.