WASHINGTON (AP) — Twelve Russian intelligence officers were indicted on charges they hacked into Democratic email accounts during the 2016 U.S. presidential election and released stolen information in the months before Americans headed to the polls, the Justice Department said Friday.

The indictment — which comes days before President Donald Trump holds a summit with Russian President Vladimir Putin — was the clearest allegation yet of Russian efforts to meddle in American politics. U.S. intelligence agencies have said the interference was aimed at helping the presidential campaign of Republican Donald Trump and harming the election bid of his Democratic opponent, Hillary Clinton.

The indictment lays out a sweeping and coordinated effort to break into key Democratic email accounts, including those belonging to the Democratic National Committee, the Clinton campaign and the Democratic Congressional Campaign Committee.

The charges come as special counsel Robert Mueller investigates potential coordination between Russia and the Trump campaign to influence the presidential election. The indictment does not allege that Trump campaign associates were involved in the hacking efforts or that any American was knowingly in contact with Russian intelligence officers.

The indictment also does not allege that any vote tallies were altered by hacking.

Still, Deputy Attorney General Rod Rosenstein said the internet “allows foreign adversaries to attack Americans in new and unexpected ways. Free and fair elections are hard-fought and contentious and there will always be adversaries who work to exacerbate domestic differences and try to confuse, divide and conquer us.”

Before Friday, 20 people and three companies had been charged in the Mueller investigation. That includes four former Trump campaign and White House aides, three of whom have pleaded guilty to different crimes and agreed to cooperate, as well as 13 Russians accused of participating in a hidden but powerful social media campaign to sway American public opinion in the 2016 election.

Hours before the Justice Department announcement, Trump complained anew that the special counsel’s investigation is complicating his efforts to forge a better working relationship with Russia. Trump and Putin are to hold talks Monday in Finland, a meeting largely sought by Trump.

Trump said at a news conference Friday near London with British Prime Minister Theresa May that he wasn’t going into the meeting with Putin with “high expectations.”

“We do have a — a political problem where — you know in the United States we have this stupidity going on. Pure stupidity,” he said, referring to Mueller’s probe. “But it makes it very hard to do something with Russia. Anything you do, it’s always going to be, ‘Oh, Russia, he loves Russia.’”

“I love the United States,” Trump continued. “But I love getting along with Russia and China and other countries.”