Official sources said Anand Kumar, chief of Siliguri Police Commissionerate, was shifted as DIG, Training of West Bengal police.
K Jayaraman, DIG anti-corruption branch, has been appointed the new Siliguri Police Commissioner, sources said.
A clash between the two parties took place after bottles filled with liquid were allegedly thrown from CPI(M) party office when a procession of Trinamool workers passed by it.
The procession was taken out to protest the attack on Chief Minister Mamata Banerjee and Finance Minister Amit Mitra by activists of CPI-M affiliated SFI in New Delhi the previous day.