The federal government said hackers targeted election systems in 21 states last year, including Arizona. But election officials in this state haven’t found any evidence that voter data was manipulated.

There are few details on the hack so far, said Matt Roberts, with the Arizona Secretary of State’s Office. But Roberts expects to have more information after an October meeting with the Department of Homeland Security.

The federal government said that in most cases, election systems across the country were not breached. The government has not said who is behind the hack, but election officials in several states said the attempts could be linked to Russia.

Only Illinois reported that hackers had succeeded in breaching its voter systems.

The Associated Press contributed to this report.