"The whole nation has been shocked by the death and injury in Manchester last night of so many people, adults and children, who had just been enjoying a concert", she said. Any new information could change the current view.
Rudd said after the Manchester attack and the subsequent leaking of information, she would review how the country's intelligence is shared.
The Palace of Westminster, which houses the British Parliament, was also closed to all those without passes, and tours and events there canceled until further notice. "I know I speak for everyone in expressing my deepest sympathy to all who have been affected by this awful event and especially to the families and friends of those who have died or were injured".
That decision was made because the authorities were still trying to find the "factory" where the bomb was produced, and whether Abedi had help in assembling the device, according to a law enforcement official who spoke on the condition of anonymity because of the secrecy surrounding the investigation.
Mohammed Saeed El-Saeiti, the imam at the Didsbury mosque where Abedi's brother Ismail had been a Quran teacher, branded the attacker as someone filled with hate.
Britain's official terror threat level was raised on Tuesday to "critical", which is the highest level and means that an attack could be imminent.
The 45-year-old from Royton, Greater Manchester, was reported missing by relatives.
Police said three suspects were arrested Wednesday in south Manchester. He was a student at the University of Salford in Manchester. "This is not us", the elder Abedi told the AP by telephone.
ISIS routinely claims attacks it has no proven connection to.
At 8-years-old the youngest confirmed victim of the attack. All campaigning for the election was suspended after the attack on Monday night.
"RIP my darling precious gorgeous girl Olivia Campbell taken far far to soon go sing with the angels and keep smiling mummy loves you so much", Charlotte Campbell wrote, posting a Snapchat photo of her daughter.
In a statement, the head teacher of the Tarleton Community Primary School that she attended in the village of Tarleton, Lancashire, described her as "simply a handsome little girl in every aspect of the word".
Georgina Callander, a student, was a mega fan of Ariana Grande, with a picture of the two circulating on social media as her name emerged as the first confirmed victim. "There was nothing worrying at all until two days ago (when) I heard the news that they suspect he was the bomber", Abedi, the father of six children, said. Tweddle had reportedly gone to Manchester with a friend to pick up the friend's daughter, who was attending the Ariana Grande concert. No further details have been released. He sounded "normal", the father said, adding that Abedi had in fact visited Libya a month and a half ago.
Ramadan Abedi refuted that to the news service, saying his family "aren't the ones who blow up ourselves among innocents".
The attack was the deadliest in Britain since July 7, 2005 when four suicide bombers inspired by al-Qaeda attacked London's transport system during rush hour, killing 52 people.