Jatrabari Police Station OC Abani Shankar did not disclose the charges against Shikkhak-Karmachari Oikya Jote Chairman Selim on Saturday.
General secretary of the organisation Jakir Hossain said Selim was picked up from the A K Degree College at Shanir Akhra.
Selim was at an inter-active meeting with the students at the time of his arrest, he said.