Five US police officers are being investigated for allegedly sending text messages filled with racist comments.

Captain Thomas Flanders and Detective Michael Sollenberger, in Montgomery County, Ohio, have been placed on paid administrative leave, while three other unnamed officers remain in post while the investigation is being conducted.

The texts emerged when copies of the messages were anonymously sent to Derrick Foward, the president of the Dayton unit of the National Association for the Advancement Coloured People (NAACP).

Mr Foward told WBTN: “These text messages, while some of them may be some joking going on back and forth, some of them are flat out rude and racist.”

The messages were filled with racist and offensive comments. One read: “I hate n******. That is all.”

Another said: “We stopped at a Walmart in Birmingham, there are a lot of Black people in Alabama. It's all Martin Luther King’s fault.”

In a particularly crude attempt at a joke, one deputy wrote: "What do apples and black people have in common? They both hang from trees."

One officer apparently threatened to stab a black person at a bar, describing them as a “coon”. Two African-American deputies were also mentioned in the messages.

Sheriff Phil Plummer of Montgomery County said: "These five individuals have taken this organisation three steps backward and will be held accountable. I will not tolerate racism in this department."

He added that while the culprits were shocked they were caught they did not apologise for their actions.

Capt Flanders, who has been in the sheriff’s office for 19 years, claimed that the allegations were completely false in a phone interview with 2 News and said he would to clear his name.

The NAACP is pressing for an external inquiry into the scandal.

This latest news comes as tensions between US police and the African-American community are running high.

'Hands Up Walk Out' Protests spread across America Show all 10 1 /10 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Activists marched on Times Square in New York Getty 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Students gathered on campuses across America Reuters 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Thousands have been motivated to campaign after the death of teenager Michael Brown in Ferguson Getty 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Michael Brown, 18, was unarmed when he was shot by a police officer Reuters 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests More students take to the streets. Although the violence of previous weeks has subsided, many remain angry about the Grand Jury's decision Reuters 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Six white and three black jurors elected not to indict white police officer Darren Wilson, in a verdict widely seen as indicative of America's 'race problem' Reuters 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests The family of the killed teenager are now allegedly considering a civil action against Mr Wilson, who has indicated he will retire from the police force Reuters 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Meanwhile, anger continues to spread across the country Getty 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests Many perceive the police force - heavily armed and in the majority of town, predominantly white - as a significant part of the problem Getty 'Hands Up Walk Out' Protests spread across America 'Hands Up Walk Out' Protests A protester is arrested in New York Getty

The shooting dead of black teenager Michael Brown - and the subsequent decision not to indict the police officer who shot him - has sparked protests across the US.

On Wednesday, a grand jury also decided not to indict the police officer who placed Eric Garner in a chokehold, leading to his death in Staten Island, New York in July.

President Obama has even said that "police brutality is an American problem".