WASHINGTON (REUTERS) - US President Donald Trump said on Wednesday (Oct 24) that threats of political violence have no place in the United States, promising a full investigation into suspicious packages that were mailed to prominent Democrats and others.

"The full weight of our government is being deployed to conduct this investigation and bring those responsible for these despicable acts to justice. We will spare no resources or expense in this effort," Mr Trump, a Republican, said at an event on opioid abuse.

"In these times, we have to unify, we have to come together, and send one very clear, strong, unmistakable message that acts or threats of political violence of any kind have no place in the United States of America."

On Wednesday, the Secret Service said it had intercepted suspicious packages sent to former president Barack Obama and former secretary of state Hillary Clinton.

Packages were also reported to have been mailed to CNN, billionaire George Soros, and other frequent, public targets of Mr Trump's scorn.