Fox News has admitted, in answer to questions from the Washington Post , that host Bill O’Reilly did not witness any bombings in Northern Ireland or murders in El Salvador. The network said he saw only photographs of such atrocities.

Related: Bill O’Reilly calls accusations of exaggerated war reporting ‘total bull****’

For more than a week, Fox defended O’Reilly from increasing accusations that he has for years exaggerated elements of his reporting. O’Reilly called such accusations “bull****” and made vague threats against reporters who do not satisfy his demands about their own reporting.

The story took on increased relevancy after NBC suspended the Nightly News anchor Brian Williams , over inconsistencies in his version of events in Iraq in 2003 and around Hurricane Katrina in 2005.

The new Fox statement is the second time either Fox or O’Reilly has backtracked on such issues.

O’Reilly claimed in a broadcast to have taken part in “a raid” in Ireland, and in a 2013 book, Keep It Pithy, wrote that he had seen “Irish terrorists kill and maim their fellow citizens in Belfast with bombs”.

O’Reilly did not see any bombings or injuries but only saw photographs provided to reporters by police, a Fox spokesperson told the Post.

Last week, O’Reilly qualified his claims of having seen four nuns murdered in El Salvador in 1980, during that country’s civil war. O’Reilly had said he saw “guys gun down nuns in El Salvador” and “nuns get shot in the back of the head”. He now says he was among “reporters [who were] shown horrendous images of violence that were never broadcast”.

O’Reilly was forced to concede that point to the liberal media watchdog Mediaite, which pointed out that the nuns were murdered in December 1980 and that O’Reilly did not travel to El Salvador until he became a CBS correspondent in 1981.

O’Reilly has claimed in broadcasts and books to have covered “four wars”, citing Northern Ireland, El Salvador, the Falklands and an unspecified conflict in Israel.

O’Reilly’s claims about his experiences in Argentina were the first to raise questions about the anchor’s truthfulness, when the liberal magazine Mother Jones found inconsistencies between his stories and eyewitness accounts. He has defended his claims that he reported “on the ground in active war zones” and “survived a combat situation in Argentina during the Falklands war”, although he has admitted that he never reported from the islands and was instead 1,200 miles away, in Buenos Aires.

Former colleagues at CBS disputed O’Reilly’s account of what happened in Buenos Aires, where he claims to have dragged to safety a cameraman who had been wounded by a rioting crowd.

O’Reilly’s coverage of the 1992 LA riots has also been called into question by former colleagues, who said they could not recollect any incident that might resemble being “attacked by protesters” or having concrete “raining down on us”, as he claimed.

Related: Bill O’Reilly’s LA riots ‘bombardment’ stories disputed by former colleagues

“It didn’t happen,” Rick Kirkham, Inside Edition’s lead reporter, told the Guardian last week. “If it did, how come none of the rest of us remember it?”

Fox has dismissed such questions as “nothing more than an orchestrated campaign by far-left advocates”.

“Responding to the unproven accusation du jour has become an exercise in futility,” a spokesperson told the Guardian in answer to questions over O’Reilly’s reporting of the LA riots. “Fox News maintains its staunch support of O’Reilly, who is no stranger to calculated onslaughts.”