Tickets for Sunday night's One Love Manchester benefit concert sold out in just six minutes this morning.
But already ticket touts are flogging them online for hundreds of pounds.
Originally sold for £40 each, tickets have been put online on websites like eBay for as much as £400 this lunch time.
"To those selling tickets on EBay for the #OneLoveManchester charity concert for a profit. Hang your head in shame," tweeted one person in reaction to the sales.
22 people were killed and many more injured in a suicide bomb attack at Manchester Arena following an Ariana Grande concert last Monday.
A charity concert headlined by Ariana will be held this weekend at Manchester's Old Trafford cricket ground.
The BBC has announced it will air One Love Manchester live this Sunday night from 6:55M live on BBC One until 10PM. The concert itself is scheduled to begin at 7:15PM.
Ariana said: "I don't want to go the rest of the year without being able to see and hold and uplift my fans".
"I'll be returning to the incredibly brave city of Manchester to spend time with my fans and to have a benefit concert in honour and raise money for the victims and their families."
As well as airing on TV, the concert will be streamed online and broadcast on both the BBC and Capital Radio networks.
BBC director general Tony Hall said: "Bringing the nation together, the BBC is proud to be broadcasting what will undoubtedly be a moving tribute to the victims and their loved ones."