A grand jury indicted a northwestern Indiana man on five charges stemming from a pipe bomb explosion at a post office, U.S. Attorney Thomas L. Kirsch II announced Thursday.

The grand jury indicted Eric P. Krieg, 45, of Munster, on charges of making an unregistered destructive device, mailing a destructive device, malicious use of explosive materials, possessing a destructive device in furtherance of a crime of violence, and mailing a threatening communication.

Krieg is accused of mailing a package at the East Chicago post office that exploded Sept. 6, injuring a postal worker. The package was addressed to an attorney who represented an individual whom Krieg agreed to pay $45,000 to settle a lawsuit, Kirsch's office said in a new release.

Krieg also is accused of mailing a suspicious package to another person on Sept. 29.

"When individuals use dangerous, explosive devices as the means to commit or attempt to commit violent acts, those individuals will be held accountable for their actions," Kirsch said in a statement.

A phone message seeking comment was left for Krieg's attorney.

A federal magistrate last month ordered Krieg, a former BP engineer and occasional political candidate, to remain jailed until trial.

Krieg is scheduled to appear Nov. 20 at an arraignment in U.S. District Court in Hammond.