By Tal Kaopan @ CNN.com, June 21

Russian government-linked hackers potentially targeted as many as 21 states' election systems last year, a Homeland Security official warned Congress on Wednesday. None of those systems were involved in vote counting, however.

DHS' acting Director of Cyber Division of the department's Office of Intelligence and Analysis, Samuel Liles, said that by late September the intelligence community concluded that 21 states "were potentially targeted by Russian government-linked cyber actors" with scanning of Internet-connected election systems. The comments came during a hearing of DHS and FBI cybersecurity officials before the Senate intelligence committee.

Liles said of the 21, a small number were attempted for an intrusion unsuccessfully, "as if someone rattled the door knob and was unable to get in," and in a small number "they made it through the door." But Liles said the intelligence community concluded that a variety of factors "made it likely that cyber manipulation of the US election system designed to change the outcome of the US election would be detected."

He added the community has a "very high level of confidence" in that conclusion.A second DHS official, Acting Director of Undersecretary, National Protection and Programs Directorate Jeanette Manfra, backed up Liles' testimony [....]