WASHINGTON (AP) - U.S. officials said that Russian hackers have targeted the networks of dozens of state and local governments in the United States in recent days, stealing data from at least two servers. The warning, less than two weeks before the election, amplified fears of the potential for tampering with the vote and undermining confidence in the results.

The advisory from the FBI and the Department of Homeland Security’s cybersecurity agency describes an onslaught of recent activity by a Russian state-sponsored hacking group against a broad range of networks, some of which were successfully compromised. The alert released Thursday functions as a reminder of Russia’s potent capabilities and ongoing interference in the election even as U.S. officials publicly called out Iran on Wednesday night.

The advisory does not identify by name or location those who were targeted, but officials say they have no information that any election or government operations have been affected or that the integrity of elections data has been compromised.

“However, the actor may be seeking access to obtain future disruption options, to influence U.S. policies and actions, or to delegitimize (state and local) government entities,” the advisory said.

U.S. officials have repeatedly said it would be extremely difficult for hackers to alter vote tallies in a meaningful way, but they have warned about other methods of interference that could disrupt the election, including cyberattacks on networks meant to impede the voting process. The interference could continue during or after the tallying of ballots if Russians produce spoofed websites or fake content meant to confuse voters about election results and lead them to doubt the legitimacy of the outcome.

A broad concern, particularly at the local government level, has been that hackers could infiltrate a county network and then work their way over to election-related systems unless certain defenses, such as firewalls, are in place. This is especially true for smaller counties that don’t have as much money and IT support as their bigger counterparts to fund security upgrades.

Officials have nonetheless sought to stress the integrity of the vote, with FBI Director Christopher Wray saying Wednesday, “You should be confident that your vote counts. Early, unverified claims to the contrary should be viewed with a healthy dose of skepticism.”

On Thursday, Chris Krebs, the head of Homeland Security’s Cybersecurity and Infrastructure Security Agency, said officials don’t have reason to believe that hackers were looking for election infrastructure or election-related information, and aren’t aware of any activity “that would allow them to come anywhere near a vote.” He said the alert was issued in regard to the scanning of county networks for vulnerabilities, not specifically to the targeting of elections.

“The election-related risk is the fact that they were in or touching an election system,” he said.