HAYWARD, Calif. (CBSLA) — A Republican California congressional candidate was attacked with a knife at a festival in Northern California over his apparent support for President Donald Trump, according to authorities.

Alameda County sheriff’s deputies responded to the attack just before 4 p.m on Sept. 9 at the Castro Valley Fall Festival, located just about three miles north of Hayward, Sgt. Ray Kelly said.

Republican Rudy Peters, who is challenging Democratic Rep. Eric Swalwell for the state’s 15th District seat in November, was working at an election booth when authorities say Farzad, 35, threatened him and attempted to stab him with a switchblade.

Fazeli “approached the victim in an aggressive manner and made disparaging remarks about his political party and elected officials”, authorities said.

“All of a sudden we hear someone screaming, ‘F— Trump, f— Trump!’” Peters told the San Francisco Chronicle.

Investigators believe Fazeli pulled out a switchblade knife and attempted to stab Peters, but the knife malfunctioned. Then, authorities say, Peters became involved in a physical struggle with Fazeli.

At one point, Peters – whose campaign website features Trump’s “MAGA” acronym – used a sign from a nearby cupcake booth and used it to shield himself from the attack, according to the Chronicle.

Fazeli fled the scene but was detained a short time later by deputies, who found a switchblade knife on his person.

He was arrested and later charged with felony assault, criminal threats, brandishing a weapon and possession of a switchblade knife.

No serious injuries were reported.

In a tweet Tuesday, Peters’ opponent wrote he was “glad to hear Mr. Peters is okay” and condemned the use of violence.

On Sunday, my opponent @PetersCongress was attacked at his campaign booth in Castro Valley. I’m glad to hear Mr. Peters is okay. But it’s NEVER okay to use violence to settle political disagreements (or any disagreement). Fortunately, @ACSOSheriffs arrested the suspect. — Eric Swalwell (@ericswalwell) September 11, 2018

According to his campaign website, Peters is a U.S. Navy vet and small business owner who worked for Lockheed Martin, General Dynamics, and other defense firms.

Fazeli is a state licensed security guard, according to documents cited by the Chronicle.