Authorities are asking for the public’s help identifying three men who assaulted a father and son outside a Toluca Lake bar in an unprovoked attack last summer.

The incident occurred about 2 a.m. Aug. 29 when the victims left a pub.

One of the assailants approached the younger victim “in an aggressive manner, appearing to start a fight,” Los Angeles police officials said in a news release Thursday.

When the father stepped in to separate the men, the assailant punched him in the face “for no apparent reason,” causing the victim to lose consciousness and fall to the ground, police said.

When the son tried to protect his father, he was also punched and fell to the ground.

All three assailants then punched and kicked both victims while they were on the ground, police said.

The attack ended when witnesses approached the scene to help.

The father suffered a broken nose, broken ribs and bruises throughout his body, while the son had bruising and scratches throughout his body, police said.

The first man is described as being about 20 to 30 years old, is about 6 feet tall and weighs about 170 to 180 pounds. He was wearing a gray hat, a purple Toronto Raptors jersey, blue jeans and gray shoes.

The second man is described as being 25 to 30 years old, is about 5 feet 10 to 5 feet 11 and weighs about 170 to 180 pounds. He was wearing a blue shirt, light blue jeans, white shoes and had “blonde bushy hair.”

The third man was described as being 45 to 50 years old, is about 5 feet 10 to 5 feet 11 and weighs about 180 to 190 pounds. He was wearing a black shirt, long black shorts, black shoes and had “cauliflower ears with his hair pulled back in a bun,” as well as the lower half of his head shaved.

LAPD officials released surveillance images of the men Thursday.

Anyone with additional information about the incident or the assailants can call North Hollywood police Detective Avina at 818-754-8461 or Detective Fournier at 818-754-8451.