Kolkata/IBNS: Security has been tightened across West Bengal Chief Minister Mamata Banerjee's office Nabanna where students under the banner 'Chhatra Samaj' have planned to reach in a rally on Tuesday afternoon protesting against the rape and murder of a 31-year-old trainee doctor at Kolkata's RG Kar Medical College and Hospital.

The students will surround Nabanna, which is located in Kolkata's neighbouring district Howrah, with the demand for Mamata's resignation over the incident.

The students are expected to gherao Mamata Banerjee's office at around 2:30 pm.

Police have claimed the students- under the banner Chhatra Samaj- haven't sought permission for the rally and just informed them.

The police claimed they have intelligence input that some miscreants will slip into the students' rally to create trouble.

The students cleared they would march to Nabanna and demand Mamata's resignation but won't resort to any kind of violence.

To thwart the rally, police have erected long barricades, placed guardrails and containers at various roads leading to Nabanna anticipating students' massive gathering.

Chief Minister Mamata Banerjee, who is facing massive public ire over the RG Kar incident, reached her office at around 10:50 am.

Kunal Ghosh, a leader of the ruling Trinamool Congress, accused the Opposition of holding the rally in disguise of students.

"The rally is being conducted by the BJP and a section of CPI-M," said Ghosh, though the Left has said it has no participation in the march.

The BJP claimed the rally was called by the students to whom it has full support.

The trainee doctor was allegedly raped and murdered at the seminar hall of RG Kar Medical College and Hospital, which is located in North Kolkata's Belgachia area on the intervening night of August 8 and 9.

One person, a civic volunteer, has been arrested in connection with the case but protesting students as well as the victim's parents suspect more people are involved in the case.

In a tough question for the Bengal government, which is represented by advocate Kapil Sibal, the Supreme Court asked why a post-mortem was conducted before a First Information Report.

The state administration has been asked why a FIR was filed on "Unnatural Death" even when the autopsy report claims rape and murder.

In its observation, the top court said, "I have not come across a case like this in my last 30 years, Bengal not following criminal procedure code."