WASHINGTON: The 10 suspicious devices mailed to prominent political figures this week have failed to ignite, leading investigators to believe they may have been intended to spread fear rather than inflict injury or death, according to two people with knowledge of the investigation.

Still, the same sources warned Thursday that similar devices, resembling small pipe bombs, could be lethal and are believed to be within the postal system.

Investigators reported intercepting three packages Thursday, two sent to former Vice President Joe Biden and one to actor Robert De Niro, bringing the total to 10. President Donald Trump has declined to call the threatening mailing an act of domestic terrorism, and has pivoted from his initial plea for national unity to blaming the media for stoking anger in the nation.

The latest would-be pipe bombs, which did not detonate, were similar to the crude devices intercepted Monday that were sent to former President Barack Obama, Hillary Clinton, former Attorney General Eric H. Holder Jr., former CIA Director John Brennan, investor George Soros and Rep. Maxine Waters, a Los Angeles Democrat. All of the recipients, including Biden and De Niro, have been critics of Trump and have been assailed by him, including in his frequent political rallies.

—Los Angeles Times