The man who blew himself up and killed and injured dozens of others at the Ariana Grande concert this week was a 22-year-old British-born man of Libyan descent. He had recently returned from Libya.
Libyan authorities arrested family members of the man in that country, and UK police and special forces forced their way into residences in Manchester, making multiple arrests of family members and other relations.
Authorities have commented that the man was from Moss Side, Manchester, where they have thwarted a large number of recent attempts from the largely Muslim immigrant population (34% Muslim VS 36% Christian VS smaller numbers of other religious affiliations).
Authorities are of the opinion that the man was not alone, and may not have made the weapon himself. They consider another attack "imminent."
The army was brought in to protect key landmarks like Buckingham Palace, Westminster Abby, and Piccadilly Circus -- a very rare occurrence.
British citizens expressed fear and a sense that Manchester "feels like a different place," testimony to the success of the Islamic extremists involved, whose goal includes just that.