From BBC -UK Terror threat raised to critical - see http://www.bbc.com/news/uk-40023488

Police have named Salman Abedi, 22, as the suspected bomber.

Eight-year-old girl Saffie-Rose Roussos, from Lancashire, named as victim of Manchester Arena attack

Twenty-two people have been killed and 59 injured in a suicide bombing at Manchester Arena at the end of a concert by US singer Ariana Grande.

• The explosion happened shortly after Ariana Grande left the stage and afterwards the 23-year-old actress-turned-singer, tweeted: "broken. from the bottom of my heart, i am so so sorry. i don't have words"
• Flags are flying at half mast outside Number 10 and political parties have suspended general election campaigning.
• Theresa May has chaired a meeting of the government's emergency Cobra committee and is expected to travel to Manchester later
• London Mayor Sadiq Khan said the police presence in the capital would be stepped up
• World leaders have expressed solidarity with the UK, including US President Donald Trump, who called those responsible "evil losers".
• Exam boards are telling schools directly affected by the attack that they can re-arrange GCSE and A-level exams in the wake of the attack
• Police have established a help centre at Manchester City's Etihad Stadium, access Gate 11, for anyone who needs assistance in tracing loved ones
• The Queen has expressed her "deepest sympathy" with all those affected, adding that "the whole nation has been shocked by the death and injury"
• The Arndale shopping centre in Manchester was briefly evacuated earlier, but has now reopened. A man has been arrested in connection with an incident there

Analysis: Gordon Corera, BBC security correspondent