(CNN)Russian government-linked hackers potentially targeted as many as 21 states' election systems last year, a Homeland Security official warned Congress on Wednesday.
DHS officials: 21 states potentially targeted by Russia hackers pre-election
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. Liles did not specify which 21 states he was referring to.
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.
"We have evidence of ... election-related systems in 21 states were targeted," she said.
Senate intelligence committee chairman Richard Burr asked if any evidence votes were changed by these Russian cyber efforts, all three witnesses -- Liles, Manfra, and FBI Assistant Director for Counterintelligence Bill Priestap -- all said "no sir."
The hearing -- which was designed to focus specifically on elections infrastructure and not Russian hacking writ large -- frustrated lawmakers in how little information witnesses were able to share.
Aside from the total number of states, the government representatives would not discuss which specifically were targeted or how many were breached. Manfra said that all "system owners" in those states had been contacted about the incidents, but that may not invlude state election officials.
The top Democrat on the panel, Virignia Sen. Mark Warner, repeatedly expressed his exasperation.
"I understand the notion of victimization, but I do not believe our country is made safer by holding this information back from the American public," Warner said.
Democratic Sen. Martin Heinrich asked Priestap whether the Russians were "successful" in their goals, which Priestap earlier outlined as sowing chaos and undermining faith in the election process as well as harming Democratic presidential nominee Hillary Clinton and benefiting President Donald Trump.
Preistap responded that observers "could argue either way."
"I don't know for certain whether the Russians would consider themselves successful," he said. "In many ways, they might argue that because of the time and energy we're spending on this topic maybe it's distracting us from other things, but on the other hand (what this committee has done) ... in terms of raising awareness of their activities ... in my opinion they've done the American public a service in that regard."
Heinrich also asked Priestap to explain the concept of an "unwitting agent," and then asked if Trump became such an unwitting agent of the Russians by talking about rigged elections.
"I can't really comment," Priestap said after a pause.
"I don't blame you for not answering that question," Heinrich said, prompting laughter from the room.
Republican Sen. Tom Cotton brought up that Clinton could also be an unwitting agent for all her blaming of the election loss elsewhere, another comment Priestap said he would not comment on.
Democratic Sen. Joe Manchin asked if there has been any result of US sanctions on Russian activity in regards to cyberatttacks.
"They have less people to carry out their activities," Priestap said.