President Donald Trump denounced political violence on Wednesday, urging Americans to settle their differences by voting.

“There is one way to settle our disagreements,” he said. “It’s called peacefully at the ballot box. That’s what we want.”

The president made his remarks during a political rally in Wisconsin after several improvised explosive devices were sent to prominent Democrats across the country. None of the devices exploded.

Trump clearly decried political violence in response to the threats.

“Any acts or threats of political violence are an attack on our democracy itself,” he said. “No nation can succeed that tolerates violence or the threat of violence as a method of political intimidation, coercion, or control.”

He vowed to investigate and prosecute the people responsible for sending the devices

“Such conduct must be fiercely opposed and firmly prosecuted,” he said. “We want all sides to come together in peace and harmony. We can do it.”