Thousand Oaks, California - A California community college professor was charged Thursday with involuntary manslaughter for the death of a Jewish man at a pro-Palestinian demonstration where an altercation broke out, local authorities said.

Loay Alnaji (50) was arrested and remanded into custody, the Ventura County Sheriff's Office said. He is being held in lieu of a $1 million bail.

Alnaji was charged with involuntary manslaughter and battery causing serious bodily injury, the county district attorney's office said.

Police say Paul Kessler (69) died from an injury to his head after an altercation with Alnaji on November 5 in Thousand Oaks, site of a confrontation between pro-Palestinian and pro-Israeli protesters.

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During the face-off, Kessler fell backward and hit his head on the ground. He died the next day in the hospital.

Footage on social media appeared to show Kessler lying on the ground clutching his head.

Alnaji was detained after the incident, and his home searched, but police released him for lack of evidence.

Witnesses provided "contradictory statements on the nature of the altercation and the identity of the assailant," according to the sheriff's office.

According to the county coroner's office, Kessler also had a nonlethal wound on the left side of his face.

Authorities said Alnaji had been cooperative with authorities and was among people at the scene who dialed 911 for emergency help after Kessler hit the ground.

Media sources identified Alnaji as a professor of computer science at Ventura Community College.

Neither the sheriff's office nor the district attorney said what new evidence emerged that led to the filing of the criminal charges.

A news conference with the district attorney and Ventura County Sheriff Jim Fryhoff was called for Friday morning.

The United States, which has the largest Jewish population in the world after Israel, has seen a rise in tensions between pro-Israeli and pro-Palestinian groups in the past five weeks.

In early October, a six-year-old Muslim boy was stabbed to death near Chicago by a 71-year-old man, a crime directly linked to the renewed outbreak of violence in Israel and the Occupied Territories, according to the police.

The Thousand Oaks incident came a month after Hamas' military wing launched an attack on Israel from the Gaza Strip after decades of violent Israeli occupation. More than 1,400 people, mostly civilians, died and over 240 hostages were taken, according to Israeli authorities.

Israel's retaliation, which has involved an extensive bombing campaign and an intensifying ground invasion of the besieged Gaza Strip, has claimed more than 11,300 lives, according to the local health ministry.