A California Sikh man’s turban was knocked off his head and his hair cut off in a beating Bay Area Sikhs are calling a hate crime.

The Sikh Coalition sent a letter to prosecutors and police on Friday asking them to investigate the Sept. 25 attack on Maan Singh Khalsa for enhanced charges under state hate crimes laws.

A group of men in Richmond punched Khalsa in the face, yelled, “Cut his f—ing hair,” and pulled his head out of his car to cut off a fistful of his religiously-mandated unshorn hair, according to the coalition. Khalsa, a 41-year-old IT worker, was hospitalized and may lose part of a finger.

The attackers “intentionally targeted his articles of faith when they knocked off his turban and deliberately cut his unshorn hair with a knife,” the Sikh Coalition said. “Targeting a Sikh’s turban and hair is analogous to targeting a Jew’s yarmulke or a Muslim’s hijab.”

Richmond police have arrested two men, and investigators were reviewing the case over the weekend as they consider charges. Officers captured Chase Little, 31, and Dustin Albarado, 25, two out-of-state contract workers for a local refinery, shortly after the attack.

Khalsa had stopped at a red light while driving home around 9 p.m. when someone tossed a beer can at his car from a Ford F-150 pickup truck on Hilltop Mall Drive Sept. 25, according to the coalition.

Five or six white men in their 20s or 30s shouted curses at him when he rolled down his window to ask them about the can, Khalsa said. One of the men even got out of the truck and started walking toward Khalsa’s car. The traffic light turned green, though, so he drove away. Khalsa called the police, but the truck stopped near him at the next red light. He said three men got out and beat him through the open window, using a knife to cut off some of his hair.

An ambulance later rushed him to the emergency room. Khalsa’s injuries included cuts requiring stitches on his fingers and hands, a black eye and dental damage that cost him $2,200 out-of-pocket. One of his fingers became infected after the violent encounter, and doctors may need to amputate it.

“The attackers caused physical injuries and deep harm when they targeted my Sikh faith,” Khalsa said in a statement released by the coalition. “I urge a thorough investigation so we can address the tide of violence and bigotry in this country.”

Sikhs refrain from cutting their hair to keep it in a natural state as an example of living in harmony with God, according to the coalition. The turban serves as a reminder to uphold the religion’s core beliefs.

Khalsa, an American citizen of South Asian descent, traces his roots to an area where such attacks had been the method of forcing a conversion since the 18th century, according to the coalition.

“Since then, forcibly removing or targeting a Sikh’s turban or hair has symbolized denying that person the right to belong to the Sikh faith, and is perceived as the most humiliating and hurtful physical injury that can be inflicted upon a Sikh,” the coalition’s letter said.

The coalition listed a number of recent attacks targeting members of their religion, including the August 2012 murder-suicide by a white supremacist in Oak Creek, Wis., that killed six Sikhs.

Richmond Mayor Tom Butt said in a statement Sunday that the charges against the two suspects and any others arrested would be released by the middle of the week.

“Worldwide, the Sikh people are known for their generosity, adherence to tradition and strong principles,” Butt said. “I regret that this violence has penetrated our community, and it underscores the importance of working towards establishing more connections and compassion in our society.”