A Polish family are "scared to go out on the streets" after a racially motivated arson attack at their home.
Ewa Banaszak said her family wanted to stay but racist comments have "intensified" since the referendum.
Police said the fire was started deliberately in a shed at the house in Plymouth and a "hate-filled letter" containing threats was sent.
The Polish Embassy confirmed a consul would visit the city on Friday and said "we are very saddened by this attack".
Insp Darren Green, of Devon and Cornwall Police, said: "I am appalled by this crime. Hate crime has no place in Plymouth and we will do everything possible to locate those responsible."
The fire happened overnight on Wednesday in Efford in Plymouth.
'Intense after referendum'
Ewa Banaszak, aged 22, has lived in Plymouth with her family for nine years. She described what happened: "My sister was in the bathroom and noticed the shed was on fire from the garden.
"The shed contains bicycles, an electric lawnmower and trimmer - there wasn't any fuel in it. My dad used the hose to try and fight the flames. It wasn't working well so he opened the doors and hosed inside."
Ms Banaszak told the BBC she "didn't feel safe any more".
"It has been very intense after the referendum, with people saying 'go back to your own country'. We've had verbal comments over the last couple of years but it has intensified after the vote and now this, which is the most serious incident yet.
"We have been here for such a long time. I will always be Polish but this is our home, where we live and work. People are scared to go out on the streets and speak Polish. We won't go back."
Ms Banaszak's sister, fourteen-year-old Aleksandra Abalmowicz, said: "Me and my sister were in my room. We saw bright orange flames. I started screaming to my mum, and Dad ran outside.
"It was so terrifying, I was really scared. A lot of people dislike our family because I'm Polish and I've been bullied at school."
Officers have been carrying out forensic examinations of the fire scene and the letter.
Insp Green said: "We believe this fire was started deliberately, was racially motivated and could have endangered the lives of the occupants."