Russian hackers targeted 21 U.S. states' election systems in last year's presidential race, a Department of Homeland Security official told Congress on Wednesday.
Jeanette Manfra, the department's acting deputy undersecretary of cyber security, would not identify which states had been targeted, citing confidentiality agreements. She reiterated that there was no evidence that any actual votes were manipulated.
"As of right now, we have evidence that election-related systems in 21 states were targeted," Manfra told the Senate Intelligence Committee, which investigating Russia's meddling in the 2016 presidential election. Systems were breached in a smaller number of states, she said, but did not give a specific figure.
Department officials had said about 20 states had been probed by hackers working on behalf of the Russian government, but recent news media reports had suggested the number could have been far higher.
Mark Warner, the top Democrat on the Senate panel, expressed frustration at Manfra's refusal to identify which states had been targeted.