A Topeka man has been charged with conspiracy in a plot to bomb the Fort Riley military base.

A court document unsealed Tuesday but initially filed April 23 alleges Alexander Blair conspired with John T. Booker Jr. in the planned attack. Blair previously had only been charged with knowing about the plot but failing to report it to authorities.

His attorney, Christopher Joseph, acknowledges the new conspiracy charge is more serious, but won't comment further.

The government alleges in the document that Blair gave money to Booker on March 17 to rent a storage unit in Topeka to store components he believed would be used to build an explosive device for the attack at Fort Riley.

Booker faces charges including attempting to use a weapon of mass destruction.