(CNN) — Federal investigators said Tuesday (Oct. 8) they’re now probing three cases of sabotage aimed at electrical substations and transmission lines in rural Arkansas, including attempts involving a tractor and a moving train.
The most recent, on Sunday, knocked out power to thousands of people over the weekend, the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives reported. The agencies issued a $25,000 reward for information in that incident and two others dating back to late August.
In Sunday’s attack, someone cut into, then used a tractor, to pull down two electric poles near Cabot, about 25 miles northeast of Little Rock.
“A power outage resulted which affected approximately 10,000 customers in the Cabot area,” the FBI said.
The power lines were owned by First Electric Cooperative. But the two previous attacks, in August and September, targeted high-voltage lines and a substation owned by the multi-state utility Entergy.
Someone brought down one of Entergy’s high-voltage transmission lines in Cabot on August 21, while a control house at a substation in Keo, about 25 miles south of Cabot, was set ablaze on September 29, the FBI said.
The FBI said it’s investigating whether the attacks are connected, and investigators suggested the perpetrator in the first had “above-average” electrical skills.
In the substation fire, the suspected arsonist left behind a message: “You should have expected U.S.” was inscribed on a control panel, the bureau reported.
In the August incident, someone attempted to use a cable to catch a moving train to bring down the tower, Entergy spokeswoman Julie Muntsell said. The perpetrator also removed bolts from the base of the 100-foot tower, contributing to its downfall, she said.
The FBI said removing bolts from the tower “would have created substantial noise” during the early-morning incident, the FBI said in a written statement.