WHITESIDE COUNTY, Illinois -- Update: Whiteside County Sheriff John Booker says agents and officers were at a mobile home near Thomson, Illinois Thurday, serving a federal warrant.
Officers began surveilling the area Wednesday morning.
A neighbor tells News 8 he saw an officer pull over a black pick-up in the driveway Wednesday and later several squad cars blocked the end of the driveway.
Sheriff Booker says the investigation has been sealed and is being handled by the FBI.
Earlier: FBI agents and a bomb squad were deployed along Route 84.
News 8's Katherine Bauer saw one person with a hazmat suit and others wearing masks.
Route 84 was closed down for part of the day between Fulton and Thomson. The road opened back up around 1 p.m.
Earlier, responders were seen near Great River Road Antiques, an employee told News 8.
The situation started yesterday, the employee said, but more officers were at the scene today. The employee did not want to be identified by name.
The employee told News 8 there was a large, green military-type vehicle and a bomb squad vehicle.
"I've never been around anything like this before," the employee said.
The employee said the officers were there by 9:30 a.m.
A Whiteside County Sheriff's Office dispatcher said they were assisting, but that there was nothing more they could say about the situation.
Janet Glazier sent in a video of a large police presence at a trailer on Route 84. It's believed this is part of the same presence seen near Great River Road Antiques.
This is an ongoing story and will be updated as more information is available.