The federal government told election officials in 21 states today that hackers targeted their systems last year, although in most cases the systems were not breached.

President Donald Trump’s official portrait from Wikimedia Commons.

The government told The Associated Press that more than 20 states were target by hackers believed to be Russian agents before the 2016 elections. However, calls today from the Department of Homeland Security were the first official confirmation of whether their states were on the list.

States that confirmed they were targeted include Alabama, Arizona, Colorado, Connecticut, Illinois, Iowa, Maryland, Minnesota, Ohio, Oklahoma, Pennsylvania, Virginia, Washington and Wisconsin.

The US government did not say who was behind the hacking, but election officials in three states said the attempts could be linked to Russia.

The AP said that Wisconsin Election Commission said the state’s systems were targeted by “Russian government cyber actors.”

Federal officials said that in most of the 21 states, the targeting was preparatory activity such as scanning computer systems. The AP says that targets included voter registration systems but not vote tallying software. Officials said there were some attempts to compromise networks but most were unsuccessful.

The disclosure to the states comes as a special counsel probes whether there was any coordination during the 2016 presidential campaign between Russia and associates of Donald Trump.

The AP said that only Illinois reported that hackers had succeeded in breaching its voter systems and Colorado said the hacking wasn’t quite a breach.

Trump has called the Russia story a hoax. He says Russian President Vladimir Putin “vehemently denied” the conclusions of American intelligence agencies.