Some $2.5 million was apparently stolen from an armored truck Thursday night during a gas station stop off I-15. One of three security guards assigned to the truck is being sought.

Detective Kenny Adams of the Box Elder County sheriff's office said the guard, whose identity has not been disclosed, "turned up missing and hasn't been seen since" the 6:30 p.m. incident at a Texaco station involving a Wells Fargo armored truck.Adams said the loss was reported to authorities by the other two security guards aboard the truck, which was on its way to Salt Lake City from Boise.

The Wells Fargo Armored Service Corp. office in Salt Lake City referred calls about the incident to the company's Atlanta headquarters. But no one was available there Friday to comment.

An eyewitness reported seeing a number of Box Elder County deputies surround the armored car between 7 and 8 p.m. with their pistols drawn. The eyewitness said no one was found inside the truck.

The FBI has been brought into the case because the money involved was headed to or from a federally insured bank, said Cal Clegg, spokesman for the Salt Lake FBI field division headquarters.

Clegg declined to say whether authorities believed the missing man was still in the area or had fled with the money.