Three men were arraigned Thursday in connection with an alleged assault on two Mexican nationals in the Tenderloin in which the suspects yelled “white power,” San Francisco prosecutors said.

District Attorney George Gascón cited the “brutal” attack as evidence that hate crimes and white supremacist groups are on the rise in The City.

He did not offer statistics to back up his claim, but said his office had been in contact with police and federal authorities about the situation.

Robert Allen, 38, Anthony Weston, 32, and Justin Meskan, 29, pleaded not guilty to charges of assault and battery with hate-crime allegations.

Prosecutors said the three men and two others who have not been arrested attacked two undocumented immigrants outside the Nite Cap bar at 699 O’Farrell St. about midnight Nov. 10.

Assistant District Attorney Victor Hwang said one of the victims was surrounded by five men “who punched and kicked him in the face, putting boots to him, while he was being held down — to the point of unconsciousness.” Another man who came to his aid was similarly attacked.

Hwang said witnesses heard the men yelling “white power.”

“This is an act of extreme violence, an act that raises a great deal of concerns for our office, and should raise many concerns from the entire community,” Gascón said.

Weston’s attorney, Stuart Hanlon, said he didn’t believe the case was a hate crime, calling it a “barroom fight.”

A trial is scheduled for late April. If convicted, the men face up to 10 years each in prison.

Seth Steward, a spokesman for the District Attorney’s Office, said prosecutors have been filing more hate-crime cases recently.

Not all those prosecutions have been successful.

In November, a jury acquitted Christopher Brymer, a homeless man and former NFL lineman accused of a racially motivated attack against a black man in July.

Katherine Dunbar, a young woman accused in a hate-crime graffiti spree, also was acquitted of hate crimes, but convicted of vandalism.

aburack@sfexaminer.com