It emerged that Istanbul was a mere transit stop for Salman Abedi before he flew to Europe. As this became known, Donald Trump promised to deal with security leaks that led to the bomber's name being leaked.
The suicide bomber who killed 22 people in Manchester passed through Istanbul on his way to Europe, but there were no records of him entering Turkey or Syria during his travels, two Turkish security officials said on Thursday.
The officials told Reuters that Turkey received no prior warning from European countries about the bomber, Salman Abedi, so he was allowed to travel on to Europe.
Abedi blew himself up outside the Manchester Arena on Monday evening killing 22 people, including young children, who were leaving a concert by US singer Ariana Grande.
Born in Manchester to Libyan parents, Abedi had recently returned from Libya, according to Britain's Home Secretary, Amber Rudd.
Not Turkey or Syria
Describing Abedi's movements before the attack, one of the Turkish officials said: "There is flight traffic before his arrival to Europe. He travels first to Europe, then to a third country and then to Istanbul and back to Europe."
"He has not spent any time in Turkey (and) he has not had an entry or exit from Syria during his travels, there is no such information in his records," the official said.
Abedi's father told Reuters in Libya he had last spoken to his 22-year-old son nearly a week ago by phone, and "everything was normal". He did not say where his son was at the time.
Sky News citing German intelligence, said on Thursday that Abedi had been in the German city of Duesseldorf four days before the attack.
Investigators have said they believe he was part of a wider network of militants.
"There has been no sharing of intelligence about this person in any country in Europe, including Germany, prior to the attack," the official said.
"There was also no warning that has been received by Turkey in this regard. This is why there were no limitations in his travel to Europe from Istanbul."
The attack also injured 116 people, of whom 75 were admitted to hospital and 23 remain in a very serious condition, health authorities said on Thursday.
Meanwhile in Brussels, US President Donald Trump on Thursday called for a "complete review" into how sensitive information concerning the Manchester bombing ended up in American newspapers, straining defence and intelligence ties with the British government.
"I am asking the Department of Justice and other relevant agencies to launch a complete review of this matter, and if appropriate, the culprit should be prosecuted to the fullest extent of the law," said Trump, who is in Brussels for a NATO summit.
TRT World's Jon Brain reports from Manchester.
America's top diplomat in London also condemned the recent leaking of secret information to US media and said his government would take action to find those responsible.
Acting US ambassador to London Lewis Lukens spoke to BBC Radio 4 on Thursday afternoon following a strong reaction from UK police when forensic photos from the scene of Monday's Manchester suicide bombing were published by The New York Times.
"These leaks are terrible, and again let me just say in the strongest possible terms that we condemn them and we are determined to investigate and to bring appropriate action," Lukens said.
The spat over the intelligence leak between the UK and US deepened on Thursday with reports Britain's security agencies have stopped sharing some information with their American counterparts.
Greater Manchester Police had been sharing findings with the UK's national counter-terrorism unit before they were passed to the US, Australia, Canada and New Zealand under an intelligence-sharing agreement called "Five Eyes".
But according to a BBC report on Thursday morning, the flow of information from the UK to US came to a sudden end after intelligence on Monday's bombing was leaked to American news outlets on more than one occasion and despite warnings from high-level UK officials.
"We have heard the message loud and clear from Her Majesty's government and we agree with their concerns and we're determined to take action," Lukens said.
The New York Times defended its decision to publish the photographs.
"The images and information presented were neither graphic nor disrespectful of victims, and consistent with the common line of reporting on weapons used in horrific crimes," the US daily said.
"We have strict guidelines on how and in what ways we cover sensitive stories. Our coverage of Monday's horrific attack has been both comprehensive and responsible," the paper added.
US journalists -- apparently acting on leaks from US officials -- were able to publish fresh details of the probe into one of the worst terror attacks in the UK only hours after Rudd expressed frustration about the revelation of the main suspect's identity.