Two teenagers, including the estranged son of a Bay Area police chief, have been arrested in another attack on a Sikh man wearing a turban in California's Central Valley, authorities said Thursday.

Tyrone McAllister, 18, the son of Union City, California, police Chief Darryl McAllister, was one of the two arrested, police in the city of Manteca, California, said.

The other suspect was identified as a 16-year-old boy whose name was withheld because he's underage. The two were taken into custody Wednesday for investigation of attempted robbery, elder abuse and assault with a deadly weapon, Manteca police said.

In an anguished Facebook statement, the Union City chief said that he has always tried to foster "community pride, trust, and public safety." His son, he said, ran away from home "a couple years ago."

"I am completely disgusted in sharing with you that, later yesterday evening, I received a call from the Manteca PD that the suspect in this horrific crime turns out to by my 18-year old son," Darryl McAllister said. "He has been estranged from our family and our home for several months now."

"Words can barely describe how embarrassed, dejected, and hurt my wife, daughters, and I feel right now," he continued. "Violence and hatred is not what we have taught our children ... "

Security video of the Monday morning attack on a 71-year-old next to a Manteca park shows one of two males kicking the victim, who goes down before getting up and trying to fend off the attackers. Then he is kicked down again, the video shows.

"Due to the elderly male not speaking English, it is not known what the two males wanted," Manteca police said in a statement. "During the confrontation, one of the males kicked the elderly male several times and spat on him. The elderly male fell to the ground after being kicked and hit his head on the ground. As the suspects left the scene, it is believed that one may have waved a firearm in the air."

The man, who was not identified, was treated at a hospital, police said.

Investigators were looking into whether the attack "meets all of the legal elements for charging as a hate crime," police stated.

Tyrone McAllister Manteca Police Dept

Last week a Sikh man putting up campaign re-election signs for a local Republican member of Congress was attacked in Stanislaus County by assailants, at least one of which allegedly said, "Go back to your country," the victim told NBC affiliate KCRA.

Victim Surjit Singh Malhi said he believed his turban protected him from the force of blows to his head.

In July the California Attorney General's office reported that hate crimes had increased 17.4 percent in 2017.