The change in status has led to speculation that that Abedi may not have been acting alone and police are investigating whether Abedi belonged to a wider network. Rudd said that it was "likely, possible, that he wasn't doing this on his own."
Police have conducted a series of raids since the attack and arrested three men in south Manchester on Wednesday. Another 23-year-old man was arrested on Tuesday.
Up to 3,800 military personnel have been made available across Britain following the attack, the Home Secretary announced, and almost 1,000 are now deployed.