Police say a second pipe bomb has exploded in a southeastern Indiana city in less than two weeks and that they think the criminal justice system is being targeted.

Madison Police Chief Dan Thurston says the latest explosion happened early Wednesday in the driveway of the home of Jefferson County Superior Court Judge Mike Hensley. It left black scorch marks. The first explosion happened March 7 across the street from the Madison Police Department.

There were no injuries in either incident. Police believe two explosions are connected.

Thurston says police see the bombings as a "directed threat to our criminal justice system."

Hensley's son, Evan Hensley, said his father "is holding up well." Federal, state and local authorities are investigating.

Madison is about 50 miles northeast of Louisville, Kentucky.