Deputy commissioner Alan Lau made the comments in a letter sent to all officers.
He accused political parties, lawmakers, the religious sector, the media and social workers of attacking the credibility of the government and supporting violence.
He said these groups are also spreading hateful and wrong ideas to students and inciting them to take part in protests, violence and anti-police action.
Lau said the false claim that the city’s police are corrupt is the root of the turmoil and hatred seen over the past few months and it must be dispelled.
He said he doesn’t expect everyone to recognise the police’s determination to enforce the law, but he firmly believes the force has the support of most of society.
Lau had overseen the police’s response to the Occupy movement five years ago. He retired at the end of 2018, but was given the temporary post of deputy commissioner of police for special duties around two months after the extradition bill crisis began.