"Happy Brexit Day" notices telling residents "we do not tolerate" people speaking languages other than English have been posted at a block of flats.
A resident of Winchester Tower in Norwich first spotted them at 06:00 GMT on Friday, as first reported in the Huffington Post.
The man, who does not want to be named, has reported the signs - which he said were on every floor - to the police.
He said: "It's heartbreaking that someone could think like this."
The UK officially left the European Union on Friday at 23:00 GMT after 47 years of membership, and more than three years after it voted to do so in a referendum.
The signs say: "We finally have our great country back... we do not tolerate people speaking other languages than English in the flats."
They go on to say "we are now our own country again" and the "Queens [sic] English is the spoken tongue here".
The resident said he discovered the first sign as he was heading out of the block in Vauxhall Street on Friday morning, and returned to his own floor where he spotted the second notice.
He alerted the caretaker, who removed the signs, and a local councillor.
The caretaker told him the notices were stuck on the fire doors on all 15 floors of the Norwich City Council block of flats for tenants who are over the age of 55.
County councillor Emma Corlett advised the resident to report the notices as a hate crime and she also contacted her neighbourhood police team.
She said: "It's a really quiet block of flats with a good sense of community spirit and a lot of people have lived there for a long time."
The resident said: "It's heartbreaking not only for those it's directed at but also for the person posting it."
Norfolk Police have been contacted for a comment.