Kolkata: A day after two key suspects in the rape and murder of a doctor at the RG Kar hospital got bail, the Left parties and the Congress on Saturday took out protest rallies at various locations in Kolkata, alleging that the CBI has "failed" to deliver justice in the case.

They also alleged that the ruling Trinamool Congress (TMC) in West Bengal and the BJP-led Centre have a "tacit understanding".

The Congress took out a procession from Rabindra Sadan area to the CBI office at Nizam Palace in southern Kolkata and criticised the central probe agency for its alleged inability to frame charges against the two accused in the case.

During the procession, Congress activists were seen holding the party flags aloft and chanting slogans like 'We demand justice' and 'Bichar chai Tilottoma (Tilottoma wants justice)'.

The police stopped the Congress activists from entering the Nizam Palace, which led to a scuffle between the protesters and the police personnel.

Hundreds of people took part in a rally, organised by the West Bengal Junior Doctors Front (WBJDF), from Karunamayee to another CBI office at CGO Complex in Salt Lake area, covering a distance of one kilometre.

Junior doctors' forum organised the march to protest the "delay in framing charges by the Central Bureau of Investigation (CBI)" against all the "conspirators" in the rape and murder of the woman doctor at RG Kar Medical College and Hospital on August 9.

The parents of the deceased medic also participated in the rally.

"We will fight for justice and it is our right," said the mother of the deceased doctor.

The protestors were holding placards which read "If the system has failed, we will make it function to deliver justice".

In a separate rally, SUCI (Communist) activists marched from Karunamoyee to the CGO Complex in Salt Lake, while a rally was taken out by SFI, the students' wing of the CPI(M), in College Street area in the northern part of the city.

The Sealdah court in Kolkata had on Friday granted bail to RG Kar Medical College and Hospital's ex-principal Sandip Ghosh and former officer-in-charge of the Tala Police Station Abhijit Mondal in the rape and murder case of the on-duty doctor.

They were granted bail after the CBI "failed" to file a charge sheet against them within the mandatory 90-day period.