One person held in the Manchester terror attack.

A 23-year-old man has been arrested in South Manchester by the police investigating the terror attack.

Greater Manchester  Police tweeted @gmpolice With regards to last nights incident at the Manchester arena, we can confirm we have arrested a 23-year-old man in South Manchester.

Meanwhile, UK Prime Minister Theresa May is giving a statement about the attack after chairing a meeting of the emergency Cobra (Cabinet Office Briefing) committee, reported the BBC.

She says people have fallen victim to a "callous terrorist attack".

The prime minister says the police and security services are working to establish a full picture of what happened.

She says a single terrorist detonated an improvised explosive device near to an exit of the venue deliberately choosing time and place to cause "maximum carnage".
She adds that the attack stands out for its "appalling, sickening cowardice"

She says that 22 were killed and 59 injured and many people are being treated for life-threatening injuries.

Many children and young people were killed, she says.

She says security services believe the attacker acted alone but they are working to find out whether he was assisted.

She says they believe they know the identity of the perpetrator but can't confirm his name.

May says a large cordon around Victoria station and Manchester Arena will remain in place "for some time".

She calls on people to give information about the attack to police.

She says the threat remains severe and a terrorist attack is still likely.

The PM says the images of people helping others "embodies the spirit of Manchester".

She says everyone in the UK stands together with the people of Manchester at "this terrible time".

She says the terrorists will never win and "our values will always prevail".