The FBI are on high alert after several law enforcement agencies in Missouri notified the bureau of a possible terrorist attack based on possibly linked instances that have occurred in the state since November. Suspicion of a possible terrorist attack comes after large quantities of propane tanks were stolen and at least 117 prepaid cell phones were purchased from at least six different Wal-Mart stores, according to RT.

At the end of November, 18-20 propane tanks were stolen from a gas station in Lee's Summit, Mo. On the same night, the CVS on Southwest 3rd Street reported the same crime. Two weeks later, 28 tanks were stolen from a CVS on East 23rd Street on Independence. At the time, law enforcement reported receiving an urgent safety email about the thefts, according to FOX's Kansas City affiliate WDAF-TV.

This however, precedes the purchase of a large quantity prepaid cellphones in less than a week, which in combination with the propane tanks has become a cause for alarm.

"Three men with accents" purchased 59 cellphones around 3:50 a.m. at one Wal-Mart near the town of Lebanon on Nov. 28, reported CBS' Missouri affiliate KRGC-TV. Authorities reportedly talked to the men, but were allowed to leave since they couldn't be detained on legal grounds. 

This was followed by reports of a purchase of several more phones on Dec. 4 in Columbia. On the same day, 48 were purchased at the Wal-Mart in Jackson and 10 at the Wal-Mart in Cape Girardeau. Another undisclosed amount were purchased at a Macon Wal-Mart on Nov. 28.

While the two aren't necessarily related, it's noted that both can be dangerous in the hands of terrorists. Since the cellphones are prepaid, they can be difficult for authorities to track. Furthermore, outside of their obvious use in communication, they can also be used as detonators for bombs, according to ABC's Missouri affiliate KSPR-TV.

Going forward, the FBI and local law enforcement encourage anyone who sees anything suspicious to contact the proper authorities.