Two groups of students clashed over collection of relief material for Nandigram victims near the Amherst Street-Mahatma Gandhi Road crossing on Friday.

The warring groups were the CPM-backed Students’ Federation of India (SFI) and the Progressive Democratic Students’ Front (PDSF). At least six students of both groups were injured and admitted to Medical College and Hospital.

SFI supporters blocked Amherst Street from 4pm to 4.30pm, disrupting traffic in several central Calcutta areas, demanding “arrest of the culprits”.

Trouble started around 3.30pm, when a group of PDSF supporters, who were marching along Amherst Street and collecting relief material, tried to enter St Paul’s College.

“The march was peaceful and people were spontaneously responding to our appeal for help. As we approached St Paul’s College, a large number of SFI students, armed with lathis and knives, attacked us,” said Amit Chakraborty, a member of the PDSF state committee.

“Three of our supporters were injured. PDSF state president Sourabh Mukherjee was injured in the head,” said Chakraborty.

SFI’s Calcutta district committee member Indrajit Ghose, however, said PDSF supporters and some Maoists were forcing students of the college to contribute to the relief fund. “When the students objected, they started beating them up. Three students were injured,” said Ghose.

Both groups lodged complaints with police.