BERLIN (AP) — German prosecutors say a man has been arrested on suspicion of blowing open railway ticket machines by filling them with gas and igniting it. They're seeking a second suspect.

Police in May warned travelers to be wary when using national railway Deutsche Bahn's automatic ticket machines because criminals attempting to break into them might have left them filled with gas.

Frankfurt prosecutors said a 30-year-old man was arrested Wednesday on suspicion of blowing open four ticket machines around nearby Fulda and stealing an unspecified quantity of cash. They said they're also looking for a 32-year-old man suspected of blowing up nine machines in central Germany.

The explosions didn't injure anyone, but several unsuccessful attempts at break-ins prompted the police warning that gas left in machines could ignite.