Police in Plymouth say they are concerned that the fear of crime has increased for members of ethnic minorities since the London bombings.
Police said racist attacks because of the bombings were unacceptable
Officers said there had been a small increase in racist incidents reported to them since July's suicide attacks.
They added that the message was that such incidents were unacceptable.
There have been no reported assaults in Cornwall, but community leaders have been in talks with police to try and stop any problems arising.
Police said they were keen to ensure that anyone who had been subjected to racism should feel able to report it.
In one incident, a 20-year-old Muslim youth received serious head injuries after he was attacked by a group of white youths in Central Park, Plymouth.
Inspector Gary Neeves from the Police Diversity Unit said: "We've had a small increase in the number of reports of racist incidents in the city. But our main concern is the increase of fear of crime in those communities.
"The fears are generally following the incidents in London that they may be targeted by people with racist views who feel justified in taking those views forward.
"We've been working with minority group support agencies, asylum agencies and the city council and we want to send a very clear message that these incidents are unacceptable and we will not tolerate them."
He added: "As a service, police are dealing with all reports of racist incidents professionally, but also sensitively and we're doing our very best to support the victims of racist crimes.
Eileen Bortey from the Council for Racial Equality in Cornwall said the council had been busyworking with police and communities to ensure people from ethnic minorities in the county felt supported.
She said: "We have been proactive and speaking to members of communities to offer reassurance and to say that there will be an immediate response if there is a need.
"Racist behaviour is unacceptable and I think that message is beginning to get through."