At least 22 people were killed and dozens injured in a suicide bombing at an Ariana Grande concert at Manchester Arena on Monday night.
Greater Manchester police have said the attacker died after detonating an "improvised explosive device" in the foyer towards the end of the concert, as thousands of people were leaving the Arena.
The Manchester Evening News has launched a fundraising appeal to raise money for the families of victims.
The We Stand Together Manchester fund on JustGiving has already raised 75% of its target of £250,000, with many people who donated leaving comments in tribute to the victims.
"Gobsmacked. Children, at the start of their lives. Awful," one person wrote.
"Donated. Our thoughts are with Manchester at this heartbreaking time," another said.
The MEN has said it will make sure the proceeds go to those who need assistance.
Hospitals in Greater Manchester have been inundated with patients suffering from shrapnel wounds after last night's attack. In response, blood donation centres in the city have seen scores of people queuing to donate blood.
So many people have offered to give blood that some have been turned away, according to reports. But Mike Stredder, Director of Blood Donation at NHS Blood and Transplant, has said people should keep blood donation appointments they have already booked – particularly those with rare blood types.
"We are responding to last night's events in Manchester. Our thoughts are with the people affected by this tragic incident," Stredder said.
"Thank you for thinking of giving blood at this time. We do have all the blood required for hospital patients at the present time.
"If you have an appointment to give blood in the next few days, please do your best to keep it, particularly if you are blood group O negative."
Don't share fake news
In the wake of the attack, many people began to share pictures of loved ones who had been at the Ariana Grande concert who were missing. Some social media users also shared fake images purporting to show missing people as a way of gaining retweets and shares, to increase the reach of their accounts.
Some images were picked up by news sites, including the Mail Online. The newspaper shared a collage of headshots of allegedly missing people, who were actually internet personalities unaffected by the Manchester Arena attack.
Other people began tweeting that a Holiday Inn hotel in Manchester had taken in 50 unaccompanied children after the bombing, which turned out not to be true.