The incident happened last week near the intersection of Keyes and Foote roads in California as the man was putting up campaign signs alone along a rural stretch on the outskirts of Keyes, the police was quoted as saying by The Sacramento Bee.
Stanislaus County Sheriff Adam Christianson said the assault is being investigated as a hate crime.
"This is a random despicable criminal act against a member of the Sikh community," Christianson said.
Sheriff Sergeant Tom Letras said the 50-year-old victim was placing signs for local candidates when two white men wearing black hooded sweatshirts ambushed him and beat him to the ground.
He was struck multiple times as the assailants screamed, "You're not welcome here!" and "Go back to your country!" They then spray painted his truck, Letras said.
"This is a heinous crime and we are aggressively investigating it," Letras said.
The victim required medical attention so an ambulance was called and he treated on scene for cuts and other wounds. According to a Facebook post, the man was beaten on the head with a rod. But he escaped major injury because of his turban, which is traditionally worn by Sikh men, the report added.
Also, the post shared an image of the pickup truck, which was spray painted in large black letters with the words "Go back to ur country" alongside a Celtic cross. The image is a well-known white supremacist symbol, according to the Anti-Defamation League which tracks anti-Semitic and other hate crimes across the country, the report added.
The department is looking for help identifying the suspects or witnesses to the crime. The incident is considered an assault with a deadly weapon and hate crime. The victim's identity is not being released at this time, Letras added.
Hate crimes against the Sikh community have raised alarm in the Central Valley numerous times over the years. After 9/11, a spate of local crimes against Sikh people were attributed to misplaced anti-Muslim bigotry.
The valley has one of the largest and oldest Sikh populations in the US. The first Sikh temple, or gurdwara, in America opened in Stockton in 1912. There are an estimated 500,000 Sikhs in the US and 25 million worldwide making it the fifth most popular religion.
Earlier, The Sikh Coalition, a national Sikh advocacy and civil rights group, issued a statement saying they were seeing a "new wave of hate crimes" against the Sikh community. It reported that Sikhs in the US are experiencing an average of one hate crime per week since the start of 2018.