Supt.

Det Ch Supt David Ferry said the arrests highlighted the ongoing efforts to catch those responsible.

Det Ch Supt Ferry said a "good response" from the public to recent appeals for information had led to some of the arrests and thanked people for their help.

Det Ch Supt Ferry also expressed concern at social media videos featuring some of the incidents.

“As a longtime part of California’s public school community, our commitment to accountability includes following the state and federal laws,” Visions in Education Supt.

"Despite the claim by organisers of today's Easter Monday parade who said they wanted to hold a dignified commemoration, what we saw was the complete opposite," Supt Gillian Kearney said in a statement.