WASHINGTON - President Donald Trump stunned the Washington political establishment on Tuesday (May 9) afternoon with the abrupt firing of Federal Bureau of Investigation (FBI) director James Comey.

The dismissal was apparently triggered by Mr Comey's handling of an investigation into Democratic candidate Hillary Clinton's actions with classified emails - an issue which had dogged her own campaign for president last year.

However, it immediately deepened the cloud of suspicion over links between the President's own 2016 campaign and the Russian establishment, which the FBI is also investigating.

Reactions to the move ranged from confusion to outrage and accusations of a pre-emptive strike by the President against a man who was supervising the probe into alleged links of figures in the Trump campaign with Russia, and Russian interference in the election to skew it in favour of Mr Trump.

"It surprised everyone, and the way Democrats are going to interpret it is that it's an effort to slow down or throw off the investigation of whatever relations there may have been between the Trump campaign and the Kremlin," University of Georgia political science professor Charles Bullock told The Straits Times.

"It (the firing) is not an indication of wrongdoing, but it can be interpreted as such."

"In so doing, (the Democrats) will further tar Comey's reputation. From the Democratic perspective, he cost Hillary the election."

Mr Comey has been drawn into politics just days before the Nov 8 election last year. He seemed to imply some wrongdoing on the part of Mrs Clinton and her staff over their handling of classified emails.

Mrs Clinton has squarely blamed the FBI chief for sabotaging what the Clinton camp thought at the time was a sure win for the Democratic Party candidate. She eventually won the popular vote but thanks to losses in key swing states, lost the Electoral College vote.

The FBI, however, has also been investigating allegations of collusion between some members of Mr Trump's campaign team, and figures in the Russian establishment.

President Trump has angrily dismissed the allegations as fabrications amplified by the "fake news media".

But his initial pick for National Security Adviser, former general Mike Flynn, had to be fired after he misled Vice-President Mike Pence on his contacts with the Russian Ambassador to Washington. Mr Flynn remains under a cloud himself because of his closeness to figures in Moscow.

But Mr Comey, in an appearance before a Senate committee last week, seemed to step deeper into a morass when he provided wrong information, saying the FBI had uncovered evidence that Mrs Clinton's aide, Ms Huma Abedin, had "forwarded hundreds and thousands of emails, some of which contain classified information" to Mr Anthony Weiner, her now estranged husband.

The FBI clarified later that while some of the emails were forwarded, it was likely the majority were just backed up on Mr Weiner's laptop.

Mr Trump, in the hand-delivered letter firing Mr Comey, cited a memo titled "Restoring public confidence in the FBI" to Attorney General Jeff Sessions, in which Deputy Attorney General Rod Rosenstein said "I cannot defend the director's handling of the conclusion of the investigation of Secretary Clinton's emails".

Mr Sessions told Mr Trump in his own letter that he believed "a fresh start is needed at the leadership of the FBI".

Democratic Party Senator Chuck Schumer swiftly called for the appointment of an independent prosecutor to pursue the probe into the alleged Russian links. Democratic Senator Mark Warner, in a television interview, said he was "flabbergasted to say the least, this President's actions are outrageous".

Democrat Senator Richard Blumenthal said on CNN: "For the President to fire someone who has him under active investigation is in my view an abuse of power."

"If there was ever any doubt about the need for a special independent prosecutor, which I've been advocating for months, there is no question now," he said. "Only a special prosecutor can hold accountable anyone who colluded with the Russians."

Some Republicans were stunned as well. Senate Intelligence Committee Chairman Richard Burr, in a statement, said: "I am troubled by the timing and reasoning of Director Comey's termination."

"I have found Director Comey to be a public servant of the highest order, and his dismissal further confuses an already difficult investigation by the Committee."

"Director Comey has been more forthcoming with information than any FBI Director I can recall in my tenure on the congressional intelligence committees. His dismissal, I believe, is a loss for the Bureau and the nation."

But Republican Senator Roy Blunt said in a statement that while Mr Comey had served the country well, "many, including myself, have questioned his actions more than once over the past year".

"I believe new leadership at the FBI will restore confidence in the organisation and among the people who do the hard work to carry out its mission."

Ms Kellyanne Conway, senior advisor to the President, defended Mr Comey's firing, telling CNN: "This is the president of the United States, he acted decisively today, he acted at the direction of his deputy attorney general. He makes complete sense because he has lost confidence in the FBI director and he took the recommendation of Rob Rosenstein, the deputy attorney general who has been on the job for two weeks."

Mr Trump, himself, addressed Mr Schumer's response to the surprise move on Twitter: "Cryin' Chuck Schumer stated recently, 'I do not have confidence in him (James Comey) any longer.' Then acts so indignant."

Cornell University professor Glenn Altschuler told The Straits Times: "It is very difficult given the timing, to accept (the director's actions on the Clinton email issue) as a credible explanation for his firing.

"President Trump had not very long ago praised Mr Comey for his handling of the Clinton emails. If he was that troubled he would not have issued such frequent pats on the back."

"Clearly it raises questions whether or not the reason for the firing is the probe into the Trump campaign's links with the Russians," he added. "When you begin to remove the people who are investigating you, certainly that will lead to the conclusion that there is a connection."

But Prof Bullock, recalling Mr Trump's criticism of US intelligence agencies and the bureaucracy during his campaign, also noted that he had promised to shake up the Washington establishment. "This fits in with a much broader narrative of populist criticism of government in general."