Facebook has refused to remove a sickening cartoon of a police officer having his throat slit from a Black Panther page used by Dallas cop killer Micah Xavier Johnson.

The gruesome image shows a man dressed in black slashing a uniformed officer's throat with a knife as blood spills out of the cop's neck.

It was posted on the 'Black Panther Party Mississippi' page, which Johnson posted a twisted rant on just days before he embarked on his massacre.

The cartoon carries the words 'as a R.B.G. killer panther I pledge to defend my black community by any means necessary'.

Facebook has refused to remove a sickening cartoon of a police officer having his throat slit from a Black Panther page used by Dallas cop killer Micah Xavier Johnson

The image has been reported to Facebook but the social media website refused to take it down, saying it does not violate the company's 'community standards'

'R.B.G' stands for red, black and green and refers to the Pan-African flag, which is often seen being flown at civil rights protests.

The picture was posted on Facebook by a user called Prince Mamuhammad, whose profile includes posts talking of 'war with the white male'.

The image has been reported to Facebook but the social media website refused to take it down, saying it does not violate the company's 'community standards'.

Facebook ruled that the picture does not 'promote graphic violence'.

Its reply to the report said: 'Reports like yours are an important rile in making Facebook a safe and welcoming environment.

'We reviewed the post you reported for promoting graphic violence and found it doesn't violate our community standards.'

Daily Mail Online has contacted Facebook for further comment.

Johnson, who was a user of a host of Facebook pages dedicated to black militancy, posted a rant on the same Black Panther Party Mississippi page five days before he shot 12 police officers in Dallas, killing five.

Facebook has refused to remove a sickening cartoon of a police officer having his throat slit from a Black Panther page used by Dallas cop killer Micah Xavier Johnson (left and right)

Army officials say Johnson was in the reserves from March 2009 to April 2015 and that he served a tour of duty in Afghanistan

'Why do so many whites (not all) enjoy killing and participating in the death of innocent beings,' he wrote above a video of what appeared to be people participating in a whale-killing.

In the disjointed July 2 post, Johnson expressed anger over lynchings of black people and 'our ancestors' being beaten, mutilated and killed.

'Then they all stand around and smile while their picture is taken with a hung, burned and brutalized black person,'Johnson, 25, wrote.

'They even go to our homeland and shoot our endangered wildlife for sport.'

Army reservist Johnson said during a four-hour siege in a parking garage in downtown Dallas that he wanted to kill white people, specifically white police officers, law enforcement officials said.

'The suspect said he was upset about Black Lives Matter. He said he was upset about the recent police shootings of black suspects. He said he was upset at white people. The suspect stated he wanted to kill white people, especially white officers,' Dallas Police Chief David Brown said.

Johnson identified himself on Facebook as a black nationalist, and his profile picture shows him wearing a dashiki and holding a clenched first in the air like a Black Panther.

He 'liked' several pages related to the Nation of Islam, the Black Riders Liberation Party, the New Black Panther Party and the African American Defense League.

A man who served in the same platoon as Johnson in Afghanistan told Fox News he 'went all Black Panther' after he returned from the war zone.

TIMELINE OF DALLAS SHOOTING 7pm: Crowd of protesters gather at Belo Garden off Main Street in downtown Dallas. 8:59pm: Just before 9pm, the first shots are heard and protesters flee the scene. 9:05pm: Video captures gunshots ringing out and officers yelling 'active shooter' around the area of San Jacinto and Griffin streets. 9:35pm: First officer is reported down. 9:40pm: Two officers down. 10:23pm: DART police reports four of their officers were shot, including one who died, Brent Thompson. 10:29pm: Chief David Brown reports 10 officers were shot by snipers and that three of those officers died. 10:53pm: Authorities raise number of officers shot to 11. This is revised to 12 on Friday morning. 11:10pm: Shots fired at El Centro College parking garage in stand-off between police and a suspect. 11:13pm: Dallas police announce that a fourth officer has died. 11:27pm: Police say a female suspect has been taken into custody. 1:35am: Police flash-bang device goes off at the scene of the stand-off at El Centro College. 1:47am: Fifth officer reported down. 3:06am: Suspect in stand-off is confirmed dead. Advertisement

Johnson wasn't the only person in his family to have developed a distrust for law enforcement. In the days leading up to the shooting, his sister Nicole wrote several posts about her frustration at the tense relationship between police and the African-American community.

She said police officers needed 'to get a taste of the life we now fear'.

Writing on Facebook, she said: 'Tired of y’all tryin to be on these cops side making it okay based off irrelevant info when our own get killed over unjust s***.'

'Man on life itself I'm beginning to trust law less n less. Come a yr from now everybody will need a gun for protection. Why is it the black get the harsh treatment like damn. Makes me so mad. When he decide we had enough n fight back smhh...' she wrote on July 6, responding to the death of Alton Sterling.

After the shooting however, she expressed utter shock at her brother's actions.

'I keep saying it’s not true,' she wrote on Facebook on Friday. 'My eyes hurt from crying. Y him??? And why was he downtown.'

'The news will say what they think but those that knew him know this wasn't like him,' Johnson added in another post. 'This is the biggest loss we've had.'

Dallas police officers Patrick Zamarripa, Michael Krol, Lorne Ahrens and Michael J. Smith, as well as DART Officer Brent Thompson, were killed by Johnson on Thursday evening.

Johnson reportedly fired from an 'elevated position', picking off officers 'ambush style,' Chief Brown said, suggesting that the shooter had some tactical background. 'Some officers were shot in the back,' he added.

Cops cornered Johnson at El Centro College at around 11pm on Thursday and attempted to negotiate, but four hours later the talks failed and a robot was brought in to detonate a bomb and kill the suspect. This was after shots had rung out at a previously peaceful protest in downtown Dallas with demonstrators screaming and running for their lives as cops dropped dead one by one.

Johnson wore body armor, which would suggest why a cop was not able to kill him when he confronted him in a one-on-one situation which was caught on camera. It resulted in the cop being executed. He also carried an AR-15 assault rifle and a handgun, and several rounds of ammunition.