The clash occured when INTTUC-affiliated Motor Workers Union held a meeting in front of the INTUC office and tried to remove the Congress trade union's flag.
Motor Workers Union president Raju Ahluwalia said the clash followed an attack from the INTUC office as four of its office-bearers were scheduled to defect to INTTUC at the meeting.
Denying any clash, Congress block president Rabi-ul-Islam said there was only a heated exchange.
Police interevened and brought the situation under control.
