The US Secret Service says agents have intercepted packages containing “possible explosive devices” addressed to former President Barack Obama and Hillary Clinton.

The agency says neither Clinton nor Obama received the packages, and neither was at risk of receiving them because of screening procedures.

It says the devices were discovered late Tuesday and early Wednesday.

A US official tells The Associated Press that a “functional explosive device” was found during screening at Bill and Hillary Clintons' suburban New York home.

The official says investigators believe the explosive is linked to one found on Monday at the compound of liberal billionaire George Soros.

The Secret Service says a second package was addressed to Obama and was intercepted in Washington.