President Donald Trump on Tuesday fired FBI Director James Comey, according to the White House.
Trump informed Comey that he has been "terminated and removed from office" based on recommendations by Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein, the White House said in a statement.
"The FBI is one of our Nation's most cherished and respected institutions and today will mark a new beginning for our crown jewel of law enforcement," Trump said in the statement.
A search for a "new permanent FBI Director" will begin immediately, the statement added.
Comey has been at the center of controversy since he disclosed a sensitive investigation into presidential hopeful Hillary Clinton in the waning days of last year's bitterly contested election.
Clinton last week blamed her loss, in part, on the decision.
Under Congressional testimony, Comey stood by his decision, saying that while the possibility that he influenced the Nov. 8 polls makes him "mildly nauseous", he believes he made the right call.
In a letter to Comey provided by the White House, the president informed the ousted FBI chief that he concurred with Sessions and Rosenstein's recommendation to remove him.
"While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgement of the Department of Justice that you are not able to effectively lead the bureau," Trump said. "You are hereby terminated and removed from office, effective immediately."
A two-and-a-half-page memo from Rosenstein said the way Comey chose to handle the conclusion of the investigation into Clinton's email "was wrong".
"As a result, the FBI is unlikely to regain public and congressional trust until it has a Director who understands the gravity of the mistakes and pledges never to repeat them," he wrote. "Having refused to admit his errors, the Director cannot be expected to implement the necessary corrective actions."
In the wake of Comey's dismissal, Republican Sen. Lindsey Graham said given recent controversies, he believes "a fresh start will serve the FBI and the nation well".
"I encourage the President to select the most qualified professional available who will serve our nation’s interests,” he added.
But the American Civil Liberties Union (ACLU) slammed Trump's decision, saying it was improper for him to dismiss the FBI director at a time when the bureau is investigating whether his presidential campaign team colluded with Russia.
“The independence of the FBI director is meant to ensure that the president does not operate above the law," Anthony D. Romero, head of the rights group, said in a statement. "For President Trump to fire the man responsible for investigating his own campaign’s ties to the Russians imperils that fundamental principle."
FBI directors are appointed to a single 10-year term that is intended to span multiple administrations in a bid to insulate them from Washington's politics.
"President Trump's dismissal of Comey raises questions about the administration's inappropriate meddling in bureau operations -- precisely at a time when the bureau appears to be investigating the president, his advisors, and his campaign for potential collusion with Russian agents in our last election,” the ACLU statement added.
Reactions continued to pour in from congressmen late Tuesday. Former Democratic presidential candidate Sen. Bernie Sanders took to Twitter to call for an "independent investigation into the Trump campaign's ties to Russia".
"It is clear that whomever President Trump handpicks to lead the FBI will not be able to objectively carry out the Russia investigation," Sanders said.
In a statement on the micro-blogging website, New York Sen. Chuck Schumer cited Trump's dismissal of former acting Attorney General Sally Yates and Attorney Preet Bharara, and said: "Now #Comey. Doesn't seem like an accident. We must have a special prosecutor.
"If we don't get a special prosecutor, every American will rightfully suspect that the decision to fire #Comey was part of a cover-up," Schumer said.
Rep. Keith Ellison echoed the need for a special prosecutor, and called Comey's removal from office "a Constitutional crisis".
Meanwhile, Senate intelligence committee chairman Richard Burr said Comey's dismissal was "a loss for the Bureau and the nation".