A bomb threat, racist taunts and graffiti are among a significant rise in hate crimes reported to Greater Manchester Police following Monday's attack, the BBC can reveal.
The force said the number of such reports had doubled to 56 on Wednesday, from the 28 reported on Monday.
Chief Constable Ian Hopkins said the force was "monitoring" the situation.
Former Chief Crown Prosecutor Nazir Afzal said the attacker was a criminal not represented by any community.
Mr Afzal, who is also head of the Police and Crime Commissioners Association, said: "It is disappointing but it happens every time.
"After Brussels, after Paris, after the murder in Westminster....There is a spike...That is sad that people are targeting a whole community just because of the action of criminals, and they are criminals. They don't represent the community.
"Jo Cox's murderer doesn't represent the white community of this country, the KKK don't represent Christianity. But that said what we have to do is encourage people to come forward and report."
Muslim leaders claim more crimes are not reported because people are "scared to talk".
Chief Constable Ian Hopkins said he could not make a "direct link" to the Manchester Arena bombing on Monday night in which 22 people died, seven of them children.
Mr Hopkins said: "Sadly we've seen an increase in hate incidents since the bomb from 28 on Monday, which is our normal average a day, through to 56 on Wednesday."
A copy of a two-hourly GMP log of reported hate crimes on Wednesday, seen by the BBC, included the following incidents relating to race or religion:
- A school received a bomb threat after some students were asked if they were Muslim
- A pupil was followed and racially abused by a man carrying a metal bar
- A bank teller was called a "terrorist" and blamed for the Manchester Arena attack by a person trying to open an account
- A person was approached in a supermarket and told "shame on you for....what you did last night"
- A woman at a supermarket was told she should not be wearing her niqab - a face veil - in public
- Racist graffiti daubed outside a property in north Manchester
South Yorkshire Police also tweeted that officers there had "seen hate crimes increase since the Manchester attack" and Essex Police said they had also seen more such incidents since Monday, but added there was no evidence of a direct link to the attack.
Other forces have issued hate crime awareness advice and urged people to report any such incidents.
In Devon, police have started an investigation after three men hurled stones and shouted abuse at a congregation at the Torbay Islamic Centre early on Saturday.
Salman Abedi, a British-born Muslim from a Libyan family, blew himself up, killing 22 men, women and children, as people were leaving an Ariana Grande concert on Monday night.
A total of 66 people remain in hospital, with 23 in critical care.
It was feared the attack might spark reprisals against Muslim people, but Mr Hopkins said the city had largely pulled together in the aftermath.
"We've seen that compassion but it is important that we continue to stand together here in Greater Manchester, particularly standing together against some of the hate-filled views that we have seen from a very small minority of the community that have no place here."
He added: "I have sent a personal message out to all the faith leaders and places of worship today and have thanked them for the support they have shown and stressed that hate crime will not be tolerated."
"It is important that people report any incidents so that they can be investigated and we can support victims and their families."
Mohammed Ullah, Muslim chaplain at Manchester Metropolitan University, said he was not surprised at the figures quoted by the chief constable.
"These are just the reported figures, other people are very scared to talk," he said.
Mr Afzal added: "I'm absolutely in awe of the people of this city. I've been at various vigils over the last few days and the coming together, the solidarity, tolerance, the acceptance is awesome.
"I would encourage people to remain undivided."