Police in Midland City conducted a second sweep of the 100-acre property on Tuesday. One of the improvised explosive devises (IED) was found inside the underground bunker where 65-year-old Jimmy Lee Dykes was killed on Monday. The other device was found in the plastic pipe Dykes used to communicate with negotiators.
The search was expected to continue through Wednesday. Dykes' body has not yet been removed from the closet-sized bunker.
Meantime, the boy he held hostage, identified only as Ethan, appears to be acting like a normal kid. He was running around, playing with a toy dinosaur and other action figures, eating a turkey sandwich and watching "SpongeBob SquarePants," relatives and sheriff's officials said.
The mother said in a statement, "For the first time in almost a week, I woke up this morning to the most beautiful sight ... my sweet boy. I can't describe how incredible it is to hold him again."
She earlier told officials that her child has Asperger's syndrome, as well as attention deficit hyperactivity disorder (ADHD). Ethan's great uncle Enfinger said on "Good Morning America" that the boy was happy to be home.
"He's very excited, and he looks good," he said.
Ethan will celebrate his 6th birthday Wednesday.
The ordeal began on Jan. 29 when Dykes killed a school bus driver and snatched Ethan. For days, officers passed food, medicine and other items into the bunker, which apparently had running water, heat and cable television.
FBI officials have offered few details about the standoff and raid that ended it. Authorities said they were able to insert a high-tech camera into the bunker and monitor Dykes' activity. They became increasingly concerned that he might act out.
ABC News has confirmed that negotiators convinced Dykes to approach the bunker door to accept delivery of an item. FBI agents set off an explosive device to gain entry to the door, according to law enforcement. Dykes fired on the agents, who fired back.
The Associated Press and ABC News contributed to this report.