President Donald Trump has accused the media of dishonesty over the number of people attending his inauguration.
Mr Trump said “it looked like” some 1.5m people had been there when he spoke at the US Capitol on Friday.
Later, his White House press secretary said it had been “the largest audience to ever see an inauguration, period”.
Neither man has produced evidence to back their claims. And photographs appear to show many more attending the inauguration of Barack Obama in 2009.
On Saturday, millions in the US and around the world protested against Mr Trump’s new administration.
The largest US rally was in the capital Washington, which city officials estimated to be more than 500,000-strong, followed by New York with some 400,000 and hundreds of thousands elsewhere, including Chicago and Los Angeles.
The aim was mainly to highlight women’s rights, which activists believe to be under threat from the new administration.
Mr Trump did not mention the protests during a bridge-building visit to CIA headquarters in Langley, Virginia, on Saturday but instead turned on the press.
He accused the media of inventing a feud between him and the intelligence community.
But outgoing CIA Director John Brennan berated Mr Trump’s “despicable display of self-aggrandisement in front of CIA’s Memorial Wall of agency heroes”.
Mr Trump said TV footage and photos of his inauguration had painted an inaccurate picture.
“It looked like a million and a half people” there on Friday, he said, disputing media reports that there were as few as 250,000 people.
He also said the crowd extended all the way back to the Washington Monument, although this claim is contradicted by aerial shots from the day.
The new president repeated his low opinion of the media dubbing reporters “among the most dishonest human beings on earth”.
Later, White House press secretary Sean Spicer also went on the attack.
“There’s been a lot of talk in the media about the responsibility to hold Donald Trump accountable, and I’m here to tell you it goes two ways. We’re going to hold the press accountable as well.”
Referring to the inauguration crowds, Mr Spicer said: “This was the largest audience ever to witness an inauguration, period. Both in person and around the globe.
“These attempts to lessen the enthusiasm about the inauguration are shameful and wrong.”
He refused to take questions.
There are no official figures for attendance. However, estimates suggest some 1.8m people attended President Obama’s inauguration in 2009 and some 1m in 2013.
A worrying debut, by David Willis, BBC News, Washington
In his first ever White House briefing, Sean Spicer rounded on reporters in a manner few here can remember.
Echoing President Trump’s charge of dishonesty earlier in the day, Mr Spicer zeroed in on reports that the attendance at Mr Trump’s swearing-in ceremony had been lower than that for Barack Obama’s inauguration in 2009 and 2013.
Mr Spicer went on to issue a thinly-veiled warning to reporters covering the Trump presidency, saying the new administration intended to “hold the press accountable”.
Precisely what he means by that is unclear, but the statement has left many veterans of the White House press pool deeply concerned.
Ultimately, of course, it begs the broader question – what will prove most unpalatable to this new administration: the messenger or the message?
In addition to the photographic evidence, Washington’s Metro system said trips were down on previous inaugurations. Marketing firm Nielsen said television views in the US were less than Barack Obama’s and Ronald Reagan’s first inaugurations.
Row with the CIA
Mr Trump’s visit to the CIA headquarters had sought to mend relations with the intelligence community after weeks of doubting their conclusions about alleged Russian interference into the US election.
“I love you, I respect you,” he said, adding that he was “1,000%” behind the spy agency.
Mr Trump said the media had invented a feud between them, although in a recent row over a leaked dossier that alleged the Kremlin held compromising material on him, he had likened the actions of intelligence agencies to Nazi Germany.
But the outgoing CIA director condemned the president’s statement at Langley.
“Former CIA Director Brennan is deeply saddened and angered at Donald Trump’s despicable display of self-aggrandisement in front of CIA’s Memorial Wall of agency heroes,” his former deputy, Nick Shapiro, said in a statement carried by CNN.
“Brennan says that Trump should be ashamed of himself.”
Last week, Mr Brennan called on Mr Trump to be more “disciplined” in what he said and warned him not to underestimate Russian intentions.