The (Nashville) Tennessean reported the threats had been cleared in at least 14 counties.
Besides courthouses, at least eight Walmart stores had been targeted, police said.
"There is no indication of any actual explosive devices" at the Nashville Walmarts, city police spokesman Don Aaron told the newspaper.
Dalya Qualls, spokeswoman for the state's Department of Homeland Security, said her department was monitoring the situation and assisting law enforcement as needed.
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