Lalbazar: Calcutta police have posted a message on their Facebook page inviting complaints against people who are demanding money to ensure admission to colleges.

Sources in the home department said the appeal by the police followed an order from chief minister Mamata Banerjee to deal with the people accused of such crime with an iron hand.

Acting on two complaints, Calcutta police have arrested four students for allegedly extorting money to arrange for seats in colleges.

An officer said more cops would be deployed in front of the city colleges from Monday so that prompt action could be taken against any complaint related to admission.

Sources said there were a number of allegations - most of which went unreported - of shortlisted students not being called to counselling at the behest of students' unions, who were trying to push their candidates.

The police circular posted on Facebook asks people to email or WhatsApp complaints about extortion related to college admission. The email ID and the WhatsApp numbers have been mentioned in the circular.

The circular states that the identity of the complainants will remain confidential.

Officers at Lalbazar failed to recall the last time such helplines were set up for complaints about irregularities in college admission.

Two students of Prafulla Chandra College - Sayan Mukherjee and Zahir Ahamed - were arrested on Saturday night on the basis of a complaint that they had taken Rs 25,000 from a candidate after promising him a seat in the accountancy honours course of the Golpark college.

"The candidate, Subhopriya Sen, came to us with the accused. The duo were booked for cheating, criminal breach of trust and criminal conspiracy," an officer of Rabindra Sarovar police station said.

Two other youths - Ritesh Jaiswal, 23, and Lal Saheb Gupta, 25 - were arrested on Friday. An officer of the detective department said "the students of Maharaja Shrish Chandra College" had been picked up based on a complaint filed by Sanjib Das.

Officials of the Shyambazar college, however, refused to confirm whether the duo were students of the institution or not.

"Das has alleged that Ritesh and Lal had demanded money from him to ensure his nephew's admission to the college. The findings of a preliminary probe suggests the allegation is true," an officer said.

Jaya Dutta, state president of Trinamul Chhatra Parishad, admitted that the accused were from her organisation. "We will take stern action against TMCP members and workers if they tarnish the image of Trinamul," Dutta said.