Updated | Man arrested in Florida over US mail bombs

A 56-year-old man has been arrested in Florida in connection with a letter bomb campaign that targeted people such as former United States president Barack Obama.

US officials named the man as Cesar Sayoc, adding the more arrests might be made.

Packages were sent out to figures deemed critical of President Donald Trump. Former Democrat presidential nominee Hilary Clinton, actor Robert de Niro and the CNN offices in New York were also among the targets.

The packages contained pipe bombs.

The nationwide search for the person or people behind the campaign had led investigators to a mail facility in southern Florida on Thursday night.

A van belonging to the suspect being checked by police (Source: CBS)

Trump has commented many times about the explosive packages being sent, however in his latest tweet he suggested that the incidents, which he described as "'bomb stuff", were having a negative impact on Republican "momentum" in early voting.

Former intelligence chief James Clapper, one of the persons who received Friday's packages, told CNN that the bombs "definitely [constitute] domestic terrorism, [there is] no question in my mind."

He said that anyone who had been critical of Trump should be alert and take additional measures to protect themselves.