Sources said the 'input' revealed that since Monday afternoon, young batches of constabulary, deployed at various police stations and units, had been circulating two audio-video clips relating to violence allegedly triggered by lawyers. A few groups of constables, active on WhatsApp, also decided to hold a protest at the PHQ and invited fellow policemen to join them.

Special Branch sources said one of the video clips related to an assault on a policeman by lawyers outside the Saket court while an audio clip revealed how a woman DCP and her subordinate were abused and roughed up during the violent clashes at Tis Hazari court on Saturday. The clips circulated on WhatsApp and Facebook by a few constables went viral in police fraternity. Reacting sharply, a few young constables from Shalimar Bagh and Mukherjinagar police station on Monday planned to stage a token protest at the PHQ by early Tuesday morning.

The protest on Tuesday, which was seen as a 'mutiny' by a disciplined force, also had the patronage of a section of senior police officers who felt demoralised, especially after the decision of the court on Tiz Hazari violence, which they viewed was one-sided.

Sources said the manner in which senior officers including a woman DCP and a local SHO were abused and roughed up by the violent mob of lawyers had caused a deep resentment among police officers. Inputs suggest that on Tuesday, several SHOs of different police stations allowed the constabulary, not only to wear black badges but also permitted them to join the protest.

Sources said that a few sub-inspectors even went out of the way and got placards and flex boards ready to display during the protests. One of the slogans inscribed on placards, "How's the Josh....Low Sir !" got a wide media attention.

Intelligence reports said that by 8 am on Tuesday, only 50-60 policemen had gathered at the main gate of the PHQ. However by 10 a.m. a few more constables in uniform arrived from nearby police stations. Families of injured policemen in Tis Hazari court also joined in a few hours.

By 10 a.m. the protesting crowd of policemen and their families swelled to around 500-600, which jammed the main Vikas Marg during office hours. Once the broadcast vans were parked on the site, the news flashed on TV sets drew more and more policemen. A Joint Commissioner of Police at the PHQ told IANS that he had specific information about a few groups of constables who played a key role in organising the protest, however, keeping in mind the "injustice" done to the police, the senior officers decided that no action should be taken against any policeman involved in the demonstration.