Chief Inspector Gilbride said he had visited the family on Sunday.
He continued: “This is an abhorrent crime and there is no room for hatred and prejudice in our society.
“We always strive to provide the best possible service to the public that we can, and provide an appropriate and expedient response.
“Where we fall short of this, we will review our approach and look to learn from it.
“We are sorry to hear that Mr Yamba has received a service below what we would seek to provide.
“I have visited him in person today in order to ensure that this incident is fully investigated as a hate crime and we do our best to ensure that whoever is responsible for this disgusting act is brought to justice.
“I would appeal to the public that if you have information which could assist the police investigation please contact us as soon as you can.”
Anyone with information is asked to call police on 101 or Crimestoppers, anonymously, 0800 555 111.