JUNE 2, 2004 - Posted at 8:52 a.m. CDT
SAN ANTONIO, TX - The theft of two full propane delivery trucks in San Antonio over the holiday weekend has federal officials worried.
The FBI says it's "very, very concerned" about the whereabouts of the trucks, citing fear of what might happen if the propane fell into the hands of terrorists.
Agent Patrick Patterson tells NBC that the theft wouldn't have drawn much attention four years ago, but has to be taken very seriously now.
San Antonio's police chief said yesterday he doesn't think terrorists are behind the thefts. But federal officials still don't want to ignore the possibility.
Another investigation is underway in the theft of 15 gas canisters from an ambulance supply company. Officials believe the two thefts appear to be a coincidence.