The FBI and San Antonio TX police are investigating the theft of two large tanker trucks carrying approximately 5,500 gallons of propane combined, from a Ferrellgas company parking lot over the holiday weekend.

The San Antonio police told Fleet Owner that the thieves cut through a chain link fence to get to the vehicles. Whether the keys were obtained or if the vehicles were hotwired is still under investigation.

“They did a very clean job,” said San Antonio police officer Grona.

According to Ferrellgas, the vehicles were properly secured in the parking lot.

“These two vehicles were stolen from a chain link fence that was locked and the vehicles themselves were locked,” Scott Brockelmeyer, Ferrellgas spokesperson told Fleet Owner.

There was no dispatcher in the parking area because they typically are responsible for the company’s 18-wheel vehicles, Brockelmeyer said. The vehicles were last used on Friday or possibly Saturday, and were discovered missing early Monday morning, he added.

“These types of vehicles wouldn’t be dispatched,” Brockelmeyer said. “I can’t recall any vehicle thefts within the six years I’ve been here— but I have heard of these thefts occurring in other companies so it’s [this incident] not unheard of,” Brockelmeyer said.

The missing vehicles were described as Kenworth T300 three-axle tractors (model years 2004 and 2003), Texas license plate numbers 8WXW38, and 7FFR20. A large oval gas tank is carried on the truck chassis emblazoned with the “Ferrellgas” logo.

Separately occurring at the same time, fifteen gas canisters containing gases that include oxygen, carbon dioxide and nitrous oxide were stolen from an ambulance supply company north of downtown San Antonio. These canisters could be used as a homemade bomb, according to CNN.com.

There is no indication that these incidents are related or linked terrorism, officials say. To see a photo of the missing truck, go to MSNBC.com.