The Police Ombudsman has been asked to investigate after two Catholic men were attacked by a loyalist mob in Portadown at the weekend.
SDLP MLA Dolores Kelly claimed that up to 30 loyalists tried to force their way into a Catholic bar in the town centre in the early hours of Saturday morning before attacking the two men while a Police Land Rover was close by.
She said she has viewed CCTV footage which clearly shows one of the loyalists sitting on top of a Catholic man and punching him with both fists before getting up and jumping on his head.
The second Catholic man was allegedly attacked with a broken bottle.
According to the PSNI a female police officer was injured during serious disturbances which flared when officers arrived at the scene.
The alleged incident occurred close to where Catholic Robert Hamill was beaten to death by a loyalist mob in 1997.
"It is only through the grace of God that there was not another death like Robert Hamill's but after viewing the CCTV footage I am in no doubt that members of this mob fully intended causing serious harm," Mrs Kelly said.
She added: "A Police Land Rover was parked at the top of the street when the men were attacked and the officers did not intervene. Because of the history of the area and the death of Robert Hamill the District Commander has very sensibly called in the Police Ombudsman to investigate this."
Sinn Féin MLA for Portadown, John O Dowd, said he was "deeply concerned" about the circumstances surrounding the attacks.
"Eyewitness reports show that the PSNI were in the area, they were aware there was a loyalist mob in Woodhouse street, a nationalist part of the town," he added.
A spokesman said: "Police, mindful of the sensitivity of the area, took the step of referring this incident to the Police Ombudsman of Northern Ireland Office in the interest of transparency and community reassurance.
"Police are treating the assaults as sectarian and continue to appeal for witnesses."