Updated:ATLANTA - Federal agents were out in force again on Thursday searching truck after truck along Interstate 20.
Channel 2 Action News reporter Mark Winne was with the agents, getting answers on what's behind the second major operation this week.
The counterterrorism operation took place along I-20 Thursday morning and into the afternoon.
Winne asked Jon Allen with the TSA if the operation was primarily a counterterrorism operation. "The focus is certainly to try to prevent any type of activity that anybody may have to disrupt transportation systems," said Allen.
The TSA said the operation is a form of highway homeland security and that federal air marshals are the lead federal agency, but other federal, state and local agencies were working the counterterrorism operation for the second time this week.
A spokesman said K-9s were looking for explosives at a truck inspection site in Douglas County. Checks for radiation appeared to be under way too, Winne said.
The big Customs and Border Protection truck-borne X-ray was also at the scene.
"Atlanta is an important transportation hub. Aside from the world's busiest airport being here, it's obviously a central trucking hub," said Jon Allen with the TSA.
Authorities said they were also checking for things like safety violations and drugs.
One truck driver who was handcuffed by authorities admitted to Winne that he had "like a dime sack" of marijuana in his truck.
Previous Stories: September 29, 2010: Counter-Terror Operation Stops Trucks On I-20