Texas law enforcement officials have charged a paramedic who helped respond in last month's deadly fertilizer plant explosion in the town of West with unlawful possession of a pipe bomb.
Bryce Reed was charged Friday with possession of an unregistered destructive device.
But law enforcement officials said they had not linked the charge to the April 17 fire and blast at West Fertilizer Company.
Fourteen people were killed in the blast, which has been treated largely as an industrial accident so far.
The Texas Department of Public Safety issued a statement saying that the agency has instructed authorities to launch a criminal probe into the blast.
Reed made an initial appearance in federal court in Waco, Texas, on Friday, but did not enter a plea.