The Kansas City Star reported the homemade explosives were discovered in a truck with Florida plates parked across the street from the Capitol in Topeka without a permit. The unidentified driver, who was wearing business clothes, was detained by authorities after being found in an underground tunnel connecting the Capitol to a state office building, the newspaper said.
In the phone call case, police said they arrested Steven J. Thibodeau of Columbia, Mo., and charged him with harassment by telephone.
"They were mad rants of anger directed at the governor," Patrick Saleh, spokesman for the Capitol Police, said.
The rally drew hundreds of people to the Capitol steps to protest illegal immigration policies advocated by Gov. Sam Brownback and Secretary of State Kris Kobach, the Star said.
"Everything seems to be independent of each other. It just occurred on the same day by happenstance," Saleh said.
The newspaper said a robotic device was brought in to remove the explosives from the pickup, which bore decals, including one that read: "Welcome to America. Now Speak English."