Cyber interference has not affected midterm vote counting, U.S. cybersecurity officials said Wednesday, as several key races that will determine whether Democrats or Republicans will control the House and Senate had yet to be called.

U.S. and local officials said that no known digital interference breached vote-counting infrastructure.

"We have seen no evidence that any voting system deleted or lost votes, changed votes, or was any way compromised in any race in the country," Jen Easterly, director of the U.S. Cybersecurity and Infrastructure Agency (CISA), said in a statement.

A few state and local governments appeared to be hit by a relatively rudimentary form of cyberattack that periodically made public websites unreachable.

ARIZONA'S MARICOPA COUNTY ELECTION OFFICIALS ADDRESS BALLOT ISSUES AMID KARI LAKE, BLAKE MASTERS LAWSUIT

The website of Mississippi's secretary of state was down for part of Tuesday and there were other reports of sites becoming unreachable throughout the country, including in Champaign County, Illinois, and parts of Arkansas.

Federal and state officials said they could not say who was responsible for the Mississippi attack or other denial of service incidents, though a pro-Russia group had called on the social media platform Telegram for its followers to target the site.

voting stickers

"I Voted" stickers are ready to be distributed to each person who filled out their ballot, Tuesday, Nov. 8, 2022, at a Brandon, Miss., precinct. (AP Photo/Rogelio V. Solis)

"While attribution is inherently difficult, we’ve not seen any evidence to suggest that these are part of a widespread coordinated campaign," said one official at CISA during a briefing Tuesday. The official spoke on condition of anonymity under rules set by the agency.           

Polling Center

CISA officials said there were no known instances of digital interference affecting the counting of the midterm vote. (iStock)

CISA and other federal agencies had warned that safeguarding U.S. elections has become more complex than ever, with the most serious threats from domestic sources. 

Foreign adversaries such as Russia, China, and Iran have tried to meddle in individual campaigns and amplify false or misleading narratives on social media.

CLICK HERE TO GET THE FOX NEWS APP

Easterly said that the post-Election Day process is continuing and may take time for election officials to tabulate votes, review procedures, and test and audit equipment before finalizing and certifying the results. 

"It's important to remember that this thorough and deliberative process can take days or weeks, depending on state laws; these rigorous procedures are why the American people can have confidence in the security and integrity of the election," Easterly said.

The Associated Press contributed to this report.