Barack Obama and Hillary Clinton targeted by mail bombs

Suspected explosive devices were sent to the former US President Barack Obama, as well as to the former Secretary of State and Presidential candidate Hilary Clinton, the US secret service said on Wednesday.

The news comes after an explosive device was found to have been sent to the home of liberal philanthropist George Soros and on the same day that CNN evacuated its newsroom after a device was sent to its headquarters at the Time Warner building in New York.

Technicians who screen mail sent to former Washington officials identified both of the devices sent to Clinton and Obama.

"Both packages were intercepted prior to being delivered to their intended location. The protectees did not receive the packages nor were they at risk of receiving them," the Secret Service said in a statement.

Also according to the Secret Service, none of the packages had made it as far as the residences of Obama or Clinton, unlike the pipe bomb identified at the New York home of billionaire philanthropist George Soros, on Monday.

Law enforcement officials said the signature is nearly the same on the three packages sent to Obama, Clinton and Soros, while at least two listed the return address as former Democratic National Committee chairman Debbie Wasserman Schultz.

A similar suspicious device was also sent to Schultz's office and is under investigation.

President Trump, who has previously butted heads with each of the packages' intended recipients, has been briefed on the situation.

White House spokeswoman Sarah Sanders said: "These terrorising acts are despicable, and anyone responsible will be held accountable to the fullest extent of the law. The United States Secret Service and other law enforcement agencies are investigating and will take all appropriate actions to protect anyone threatened by these cowards."