A 69-year-old Jewish man died on Monday from injuries he suffered during a weekend altercation in Southern California over the Israel-Hamas war, and authorities said they were investigating the incident as a homicide and a possible hate crime.

The dispute occurred on Sunday afternoon amid duelling demonstrations at an intersection in Thousand Oaks, California, a suburb about 64km northwest of Los Angeles, authorities said. Deputies from the Ventura County Sheriff’s Office responded to a call about a physical altercation at the protest site, where supporters of Israel and Palestine were present, according to the agency.

There, they found Paul Kessler with a head injury he had sustained when he fell backwards and hit his head on the ground. Kessler, a Thousand Oaks resident, was taken to a hospital, where he died a day later. The Ventura County Medical Examiner’s Office determined that Kessler had died of blunt force head injury, the sheriff’s office said.

Witnesses told investigators that Kessler had a physical altercation with at least one counter-protester, authorities said.

Word of Kessler’s fall ricocheted quickly across communities that were already on edge. Several mourners on Monday night brought flowers and lit candles on a ledge outside a Shell gas station near where the altercation occurred.

Rabbi Michael Barclay, of the nearby Temple Ner Simcha, said on Monday evening that he had been urging congregants not to share rumours and that he had previously discouraged community members from counter-protesting at pro-Palestinian demonstrations to avoid confrontations.

Hussam Ayloush, the executive director of the Council on American-Islamic Relations office in Los Angeles, denounced all violence and urged people to avoid “sensationalising such a tragedy for political gains or spreading rumors that could unnecessarily escalate tensions that are already at an all-time high.”

“We urge everyone to wait for the Ventura County Sheriff’s Office to complete its investigation before drawing any conclusions,” Ayloush said in a statement.

“Our thoughts are with the family and the Jewish community during this difficult time.”

The Jewish Federation of Greater Los Angeles said Kessler was Jewish and that he was struck in the head by a megaphone held by a pro-Palestinian demonstrator.

The sheriff’s department didn’t immediately confirm those details but.

Rabbi Michael Barclay of Temple Ner Simcha in Westlake Village, near Thousand Oaks, urged people to avoid jumping to conclusions about what happened.

“I just got off the phone with the Chief of Police,” he posted on X, formerly Twitter. “They have conflicting reports of what happened, and they did interview the suspect that is identified in social media at the event. They have no video.”

He said police are being cautious before making accusations. “We need to do the same, and not let this become a spark that starts an inferno,” he wrote.

Since the war between Israel and Hamas broke out last month protests have been held around the world. Hamas militants have been condemned for invading Israel and killing and kidnapping civilians while Israel has been accused of indiscriminate bombing that has killed many civilians in Gaza.

Blinken thanks

Top US diplomat Antony Blinken discussed the situation in Gaza with his Japanese counterpart on Tuesday, including the need to increase humanitarian aid, the state department said.

“The secretary thanked foreign minister Kamikawa for denouncing Hamas’ attacks on Israel and offering condolences for the American citizens who lost their lives,” the department said in a statement.

Blinken was in Tokyo for a Group of Seven meeting.

Japan has taken a cautious approach to the crisis, resisting pressure to fall in line with the pro-Israel stance of its closest ally, the United States, officials and analysts say.