President Donald Trump is taking aim at the FBI as the investigation continues into possible Russian meddling in the 2016 election.

  • President Donald Trump says FBI's reputation at its worst in history
  • Tweet comes as FBI agent removed from investigation
  • Some speak out in support of FBI

It comes just days after his former national security adviser, Michael Flynn, pleaded guilty to lying to the FBI.

The president’s tweet comes as a senior FBI official was removed from special counsel Robert Muller’s investigation into possible Russian meddling in the 2016 election because the agent, Peter Strzok, sent messages that could be interpreted as showing political bias for Hillary Clinton and against Trump.

Peter Carr, a spokesman for Mueller, said Mueller removed Strzok from the team “immediately upon learning of the allegations.” He would not elaborate on the nature of the accusations. The person who discussed the matter with The Associated Press was not authorized to speak about it by name and spoke on condition of anonymity.

Strzok also led the investigation into Hillary Clinton’s email server.

Former FBI Director James Comey, who was fired by Trump, responded by tweeting a quote he said back in June.

Comey was not the only one who reacted to the president's tweet.

Strzok’s removal almost certainly reflected a desire to insulate the investigators from any claims of political bias or favoritism. Trump and many of his supporters have at times sought to discredit the integrity of the investigation, in part by claiming a close relationship between Mueller and Comey and by pointing to political contributions to Democrats made by some lawyers on the team.

The Associated Press contributed to this story.