People of South Asian descent had been unfairly treated, according to advocates.

According to Mr. Newsom, the state already prohibits discrimination based on religion, origin, and other factors.

As caste discrimination is already prohibited under these existing categories, this bill is unnecessary, he said.

Hindu society is divided into rigid hierarchical groups by the caste system, which dates back more than 3,000 years.

Caste discrimination was banned in India more than 70 years ago, but biases persist, especially against Dalits, once called “untouchables.”

Last month, California lawmakers voted 31-5 to ban caste discrimination state-wide.

Democratic state senator Aisha Wahab sought to add caste to the state’s anti-discrimination laws alongside gender, race, religion, and disability.

The ban came after Seattle became the first US city to ban caste discrimination in February. There was praise and backlash to the caste bill in California, home to one of the largest South Asian populations in the country.

Hundreds of residents attended public hearings about the bill.

South Asians are “implicitly singled out” by the bill, according to the Hindu American Foundation.

After the governor vetoed the bill, the foundation said Mr Newsom had “averted a civil rights and constitutional disaster that would have targeted hundreds of thousands of Californians based on their ethnicity or religion”.

It was echoed by a number of Republican lawmakers who opposed the bill, arguing that discrimination was already prohibited under state law, and that the latest measure would lead to racial profiling of South Asian Californians.

Dalit civil rights group Equality Labs had launched a hunger strike last month to support the bill.