One of the letters.

South Yorkshire Police said three people in the county have received the vile letter, which urges people to take part in a points-scoring game by committing offences ranging from removing a woman’s head scarf to murder.

In addition to the letters being received in the area, it is believed another was sent from within Sheffield to Bradford councillor Riaz Ahmed.

Sheffield Star readers have taken to Facebook to voice their condemnation over the letters.

Wayne Darwent said: “The people behind this must be found and dealt with. They seek to terrorise and divide our rich and diverse community. They won’t succeed.”

Gail Walker added: “We want Sheffield to be a city we are proud of with communities that thrive and contribute to our prosperity. Sending out violent and clearly racist threats is appalling. "Good people need to stand up against this bigoted hatred.”

Ralph Matthewman described whoever sent out the letters as “sick people.”

The Sheffield and Balby Quakers’ group has also condemned the letter. A spokesman said members wanted to “express their deep sorrow and outrage on hearing of the letter circulated by person or persons motivated by hate.”

Counter Terrorism Policing North East has launched an investigation into the matter.

Detective Chief Superintendent Martin Snowden, head of Counter Terrorism Policing North East, said: “We take religious hatred extremely seriously and my officers will be carrying out a full and thorough investigation in response to these reports.

“They also seek to divide us. Yet in spite of this our communities have shown strength in their response to such hatred and in their support for each other.”