A police officer in San Jose, California, was put on administrative leave after he posted online comments threatening people protesting against the killings of black people by white police officers. Officer Philip White's messages on social media site Twitter triggered criticism from protesters, who are now demanding his dismissal.

The tweets were first reported on Sunday by BuzzFeed News and led to an investigation by the San Jose police department. White is reportedly on administrative leave until the investigation is complete. His Twitter handle @Coach_White3431 was also not available on Tuesday.

"It is extremely important for the community to know the comments made on Officer White’s private social media account do not reflect the thoughts or feelings of the men and women here at the San Jose Police Department. Nor do we condone this type of behavior,” Sgt. Heather Randol, a spokesperson for the police department said, according to CBS Local San Francisco.

California-based Menlo College, where White used to coach the basketball team, also distanced itself from the officer.

"Phillip White is no longer associated with Menlo College. The College will not be represented by expressions of intolerance and bigotry on the campus, on social media, or on the internet," the college said Monday, in a statement on Facebook.

An online petition demanding White's dismissal is also being circulated on the portal Change.org.

“The San Jose community is appalled by Officer Phillip White's threats to protesters through his twitter account. His words, if tolerated, make the notion of positive police-community relations impossible. Every second he has a badge and a gun, our community is at risk. He must be fired,” according to the petition, which had garnered over 10,000 supporters by Tuesday.

Twitter users, supporting the messages, "Black Lives Matter" and "I can't Breathe," got into an online argument with White who had posted messages ridiculing the protesters.