Participants of a mega rally, including prominent film personalities and rights activists, held a night-long sit-in here till 4 am on Monday, demanding justice for a doctor who was allegedly raped and murdered at a hospital last month.

Thousands of people took part in the protest march on Sunday, and at the end of the rally, they squatted in the Esplanade area in central Kolkata, vowing to be there till Monday morning to press upon the government for a swift probe into the heinous crime and arrest of the culprits.

Sunday night's protest was reminiscent of the "Women Reclaim The Night" event that was held on August 14 at midnight to demand justice for the postgraduate trainee doctor.

At the beginning of the sit-in, there was a commotion as a man in an inebriated condition entered the protest venue and allegedly misbehaved with one woman protestor, the participants of the rally claimed.

He was handed over to the police, they said.

"We had given the 4 am deadline to the administration for addressing our demand...But we did not hear anything from any state department - police, health and women and child welfare.

"At the start of the dharna, we had sent separate emails to these departments, urging them to send representatives to listen to our grievances. Not a single state representative responded or turned up at the venue," film director Birsa Dasgupta said.

Actor Sohini Sarkar said the participants of the mega rally, which commenced from College Square in northern Kolkata, will discuss how to carry forward the movement after the expiry of the 4 am deadline.

"We will not dismantle the stage erected for the sit-in," she said.

Actor Swastika Mukherjee, who was at the forefront of the protest, demanded "azadi from abuse" and strict punishment of convicted rapists.

"Our protests will become stronger from now and will continue. There will be relaxation during Durga Puja as many poor people are dependent on this festival," the actor said.

She also said, "Arresting everyone in the RG Kar case is crucial for the safety of every woman."

Actor Debalina Mukherjee, who was also at the forefront of the rally, claimed, "The administration has refused to acknowledge our demands. If they remain unresponsive, we will intensify our protests".

Protesters also painted street graffiti in red and black projecting the demands through slogans and sketches.

As the protest continued over the night, the air was filled with songs like "Karar Oi Louho Kopat", "We Shall Overcome" and singer Arijit Singh's new rendition, "Aar Kabe", dedicated to the R G Kar victim and other rape victims.

Notably, the body of the postgraduate trainee doctor was recovered from the seminar hall of the RG Kar Medical College and Hospital on August 9, and a civic volunteer was arrested in connection with the alleged rape and murder of the medic.

The incident has triggered nationwide outrage and the Central Bureau of Investigation (CBI) is probing the matter upon the direction of the Calcutta High Court.