Homeland Security Secretary Kristi Noem says federal law enforcement is investigating a social media post made by former FBI Director James Comey that she and other Republicans claim is a call for violence against President Donald Trump.

CNN aired footage showing Comey leaving his suburban Virginia home en route to the Secret Service's Washington field office.

Former FBI Director James Comey is expected to be escorted to by US Secret Service agents to their Washington Field Office on Friday afternoon, according to a law enforcement source.