Federal agents and local police are investigating an explosion outside Democratic congressional candidate Brendan Mullen's northern Indiana home.
Alcohol, Tobacco and Firearms agents say the blast Monday afternoon in a newspaper box outside Mullen's home in Granger, Ind., is among four this week in the area eight miles northeast of South Bend. ATF Indiana spokesman Dave Coulson said Tuesday that nobody was hurt and investigators believe the four incidents may be connected.
Mullen spokesman Andy Reynolds says police are investigating a bottle that was placed inside the newspaper box. Reynolds says Mullen and some campaign staff were working from the house when they heard the explosion.
Mullen is running against Republican Jackie Walorski for the northern Indiana seat being vacated by Democratic Senate candidate Joe Donnelly.