Toronto's police union is calling on the chair of the police services board to step down immediately after a poster that compares officers in the U.S. with terrorists was shared on his Facebook wall.

In a statement released on Friday, the Toronto Police Association says Alok Mukherjee "has crossed the line" after he shared an image originally posted by the activist group Occupy Wall St.

The photo has since been removed from Mukherjee's Facebook wall, but the TPA included a screenshot of the post in their statement.

It’s comprised of three images with text that said, "Americans killed by ISIS: 3," "Americans killed by Ebola: 2," and "Americans killed by police: 500 + every year."

The photo is also captioned, "I can’t breathe," referencing a cellphone video posted on the Internet that shows a white police officer holding Eric Garner, who was unarmed at the time, in a chokehold.

A medical examiner's ruling later said that chokehold contributed to his death. A grand jury decision not to bring charges against the officer involved sparked protests across the U.S., and the types of Internet posts that turned up on Mukherjee’s Facebook account.

According to the TPA, Mukherjee "has crossed the line. His lack of objectivity indicates he is no longer fit to sit on the police oversight body."

The union added that the post "not only compares police officers to terrorists but implies they are in fact more dangerous.”

TPA president Mike McCormack says Mukherjee should resign.

“How can you have somebody who is responsible for the oversight of police officers in Toronto calling our officers, and putting that out there, as if we’re terrorists,” McCormack said Friday.

Mayor John Tory, who plans to serve on the police services board, said the posting shows less than good judgment.

“I’m disappointed because I think it’s a regrettable thing for (Mukherjee) to get himself mixed into, and because I think that it reflects on … our police service,” Tory told reporters.

Mukherjee released a statement Friday afternoon explaining that the post was meant to "encourage conversation" about policing in general.

"It was not intended to be a negative commentary in any way on members of our police service or on our practices," he said. "I am very proud of our approach to policing, our practice of continuously learning from our experience, our systems of accountability and the efforts we make to maintain positive relations without community."

Coun. Michael Thompson, a past member of the police services board, defended Mukherjee.

“He did not, as I looked at the information, cast any particular position or commentary, or made any comparison or contrast with Toronto Police Services and I think it’s really important to make sure that we clarify that,” Thompson said.

The councillor added however, that he may have thought twice about putting the post on his own Facebook page.

The union says it plans to file a formal letter of complaint with Ontario Premier Kathleen Wynne, the solicitor general, Toronto Mayor John Tory, the Toronto Police Services Board (TPSB) and the Ontario Civilian Police Commission.

Mukherjee was appointed to his current position by the province. His second three-year term is set to expire in 2016.

This is not the first time the head of the TPSB has been at odds with a police organization.

Last month, his remarks about a study that suggests some officers in the Jane Street and Finch Avenue area are ignoring new carding rules were blasted by the Toronto Police Service Senior Officers’ Organization (TPSSOO).

Mukherjee told the Toronto Star that the findings in the report were "extremely disturbing and problematic," and represented a "crisis in confidence."

In response, the TPSSOO said he that he was "jumping to conclusions." The group said the study used "questionable methodology" and does not reflect what is happening in the area today.