Ohio state police will conduct daily sweeps of schools in Springfield after authorities have been forced to investigate "at least 33" bomb threats that led to evacuations and temporary building closures, Ohio Gov. Mike DeWine said Monday.

"We want to make sure, as school continues this week in Springfield, that parents have confidence that the school is in fact safe," the Republican governor said at a press conference.

Each bomb threat has been a hoax without "any validity at all," DeWine said.

Springfield has become the face of the national immigration debate after Republican presidential nominee Donald Trump and his running mate, Ohio Sen. JD Vance, repeatedly spread baseless claims about Haitian immigrants stealing and eating city residents' pets.

Vance first promoted the unfounded rumors in a Sept. 9 post on social media platform X, but Trump boosted the claims further a day later at the first presidential debate against Democratic nominee Kamala Harris.

Springfield officials, including its Mayor Rob Rue and local police, have all dismissed the claims, saying there are no credible reports that Haitian immigrants in the city are stealing or eating pets.

Local health officials have also denied that the influx of Haitian immigrants in the city has led to a rise in "communicable diseases" — another claim Vance promoted.

"This is a piece of garbage that is simply not true. There's no evidence of this at all," DeWine said Sunday on ABC's "This Week."

Bomb threats that were later proven to be false have since forced the evacuation and closure of schools and government buildings in Springfield, including City Hall. Threats have also targeted local colleges and a hospital.

The governor said beginning Tuesday, members of the Ohio State Highway Patrol field force will sweep Springfield school buildings every morning and evening, and that officers will remain on campuses during the school day.

DeWine on Monday indicated the threats were being made by non-American actors.

"We have people, unfortunately overseas, who are taking these actions. Some of them are coming from one particular country," he said, not specifying the country to which he was referring. "We think that this is one more opportunity to mess with the United States, and they're continuing to do that. So we cannot let the bad guys win."