Shares of Massey Energy Co. fell Tuesday after the company disclosed it received a citation for improperly stored explosives in the mine where 29 men were killed in an April explosion.

The company denied that there was any link between the explosives and the fatal blast.

By midday, Massey shares were down $1.01, or 3.2 percent, to $30.55.
Massey disclosed in a regulatory filing Monday that the U.S. Mine Safety and Health Administration issued an "imminent danger order" after a box of explosives was found in the Upper Big Branch mine in West Virginia on July 30.

The Virginia company said the small locked box was found between two areas involved in the explosion, deep in the mine.

Federal officials are still investigating the explosion, believed to be the nation's worst coal-mining disaster in 40 years.

Last week, the mine-safety agency released documents indicating that it has cited Massey for failing to report more than 20 accidents at the Upper Big Branch mine in the two years before the deadly explosion in April. The federal officials allege Massey failed to report roof collapses, injuries and two miners' claims of contracting black lung disease.