US authorities have detained a man in connection with the mail bombs scare that has widened to 12 suspicious packages, officials said.

Three law enforcement officials identified the man as Cesar Sayoc, 56, of Aventura, Florida.

Video from television news helicopters showed federal agents and police examining a white van in the car park of a business in Plantation, Florida. The van had several stickers on the windows, including American flags.

Earlier yesterday, authorities said suspicious packages addressed to New Jersey senator Cory Booker and former National Intelligence director James Clapper – both similar to those containing pipe bombs sent to other prominent critics of President Donald Trump – had been intercepted.

The discoveries further spurred a coast-to-coast investigation as officials scramble to locate a culprit and possible motive amid questions about whether new packages were being sent or were simply surfacing after a period in the mail system.

The devices have targeted well-known Democrats including former president Barack Obama, ex-vice president Joe Biden, Hillary Clinton and former attorney general Eric Holder.

Attorney general Jeff Sessions said the Justice Department was dedicating every available resource to the investigation, “and I can tell you this: we will find the person or persons responsible. We will bring them to justice”.