Chief Minister Mamata Banerjee told reporters in Kolkata that the assistant commandant of the IRB 2nd battalion, Kiran Tamang, was critically injured during the violence.
He has been admitted to a hospital, she said.
Earlier, IRB sources said Tamang had been killed in the clash.
GJM leader Binay Tamang claimed that two of his party workers were killed when the police opened fire at a GJM procession here.
ADG (law and order) Anuj Sharma, however, denied the allegation and said the police did not open fire.