Several children are among the 22 dead after a suicide attack hit a teen pop concert in Manchester on Monday night.
Another 59 have been injured by the improvised bomb, which was detonated by a lone wolf attacker. ISIS have claimed responsibility for the attack but gave few details of the attacker.
At least 12 children are among the wounded, several of whom are thought to be in a serious condition.
The Prime Minister condemned the 'sickening cowardice' of the attack adding her 'thoughts and prayers' were with the victims. She chaired a two-hour meeting of the security committee Cobra this morning and the panel will sit again tonight.
Church leaders are calling for prayers as the UK reels from the deadliest attack in more than a decade.
The Conservatives, Labour, Lib Dems and the Green party are suspending their election campaign in the wake of the explosion, which struck less than three weeks ahead of the general election.
The Archbishop of Canterbury, Justin Welby, tweeted he is praying for those who lost loved ones and insisting 'dark evil cannot overcome' Manchester.
Heroic Manchester, dark evil cannot overcome it. We pray for those in sorrow on the hard journey of loss & pain, & for those who protect us— Justin Welby ن (@JustinWelby) 23 May 2017
The Bishop of Manchester, David Walker, also said the city will not be defeated as he called prayers.
Please hold the people of #Manchester in your prayers. We've faced terror attacks before and this latest won't defeat us.— David Walker (@BishManchester) 23 May 2017
Pope Francis said he was 'deeply saddened' by the attack and offered to pray for the injured and all those who had died. 'His Holiness Pope Francis was deeply saddened to learn of the injury and tragic loss of life caused by the barbaric attack in Manchester, and he expresses his heartfelt solidarity with all those affected by this senseless act of violence,' a Vatican statement read. 'He commends the generous efforts of the emergency and security personnel, and offers the assurance of his prayers for the injured, and for all who have died. 'Mindful in a particular way of those children and young people who have lost their lives, and of their grieving families, Pope Francis invokes God's blessings of peace, healing and strength upon the nation.' Several pop stars also joined to offer their prayers.
To the trolls who are up and about early trying to feast on last night's tragedy. Your words condemn you themselves.— David Walker (@BishManchester) 23 May 2017
Sad, sad news from Manchester. Praying for all the victims and families involved.— Gary Barlow (@GaryBarlow) 23 May 2017
Katy Perry also added her condolences and prayers:
MY PRAYERS GO OUT TO PPL OF MANCHESTER…HAD SPECIAL TIMES THERE FROM YOUTH & BEYOND— Cher (@cher) 22 May 2017
The Church of England issued a prayer for Manchester as it called for peace.
In a blog post on Tuesday morning he wrote: 'The cowardice of the perpetrator is striking. Isn't it brave and principled to target unwitting children and young people?' He added: 'My prayer is that those whose lives have been torn apart by this atrocity will be drawn by a profound hope and not devastated by fear. 'May the crucified and risen One shine light into this darkness and bring some peace.' Nicky Gumbel, vicar of Holy Trinity Brompton, an evangelical megachurch in London, tweeted:
Horrified, shocked and deeply saddened by the depth of evil.— Nicky Gumbel (@nickygumbel) 23 May 2017
'Do not be overcome by evil;
but overcome evil with good.'
The ruling general assembly of the Church of Scotland, which meets this week in Edinburgh, will hold a minute's silence and offered its condolences and prayers for the victims.
'There is no cause, political or religious, that justifies actions of senseless brutality, anywhere or at any time,' said moderator Rt Rev Dr Derek Browning.
'The young people and their families and friends, the emergency and security services, and the people of that great city of Manchester - We pray for them and send our sincerest wishes of peace to come in this heart-rending situation.'
The Muslim Council of Britain has added their thoughts and prayers following the events, condemning the attack strongly.
Secretary general Harun Khan said: 'This is horrific, this is criminal. May the perpetrators face the full weight of justice both in this life and the next.
'I pay tribute to the police and emergency services who have worked valiantly to save lives last night. They were helped by civilians who rushed in to offer their support. I urge all those in the region and around the country to pool together to support those affected.'
Christians on the Left, a Labour-affiliated political group, tweeted:
'Even though I walk— ChristiansontheLeft (@ChrLeft) May 23, 2017
through the darkest valley,
I will fear no evil,
for you are with me.'
For #Manchester, we pray.
Rachel Mann, a priest in Manchester, added: