Islamic State (IS, formerly ISIS/ISIL) has claimed responsibility for the terrorist attack in Manchester on Monday night.
According to Amaq, a news outlet linked to the terror group, an IS member carried out the bombing which killed 22 and injured 59.
It did not give any information as to who carried out the attack.
Police say they are investigating whether the bomber was part of or was in contact with a terror network.
Intelligence officials believe they know the attacker's identity. His name has not been revealed.
IS supporters have hailed the bombing as a victory against "the crusaders" of the West.
In one video posted online, an English speaking supporter of IS held up a homemade sign with the word "Manchester" and the date of the attack.
Other IS supporters said the attack was revenge for the UK's involvement in the bombing campaign against the terror group in Iraq and Syria.
The United States says it has not yet verified the alleged IS connection to the Manchester attack, despite the terror group’s claim of responsibility.
“IS claims responsibility for every attack, we haven’t been able to verify the latest one,” Director of National Intelligence, Daniel Coats, said, reporting on the bombing in Manchester before the Senate Committee on Armed Services about Worldwide Threats on Tuesday.
“I just returned from London and met with all my security intelligence colleagues. We spent time discussing threats to our respective homelands,” said Coats, who stressed “this threat is real and is not going away.”
Coats said that, while information sharing between allies has prevented some attacks, the consensus is that individual extremist attacks are the hardest to predict.
Coats said he will be speaking to his UK counterpart after the hearing.
“IS maintains the intent and capability to inspire transnational attacks,” said Coats, adding “homegrown violent extremist pose the greatest threat to US homeland, and they are attacks with little warning.”
Dr. Samir Puri, a war studies lecturer at King’s College London, told Sky News: “As it stands, Islamic State has claimed one of its ‘soldiers’ has conducted this attack.
“There’s been no identification, there’s no martyrdom video… so one would suspect that the ISIS claim is retrospective and opportunistic, and actually they don’t have a clue who this attacker was.”
Puri added: “We should be really careful not to give too much credence to an organization that effectively operates by inspiring people it may have never had any contact with.”