Banerjee said foreign forces close to the Bharatiya Janata Party had a hand in the pro-Gorkhaland agitation.
Activists of the Gorkha Janmukti Morcha and the Gorkha National Liberation Front also clashed with the police at Sonada and Chawkbazar in Darjeeling.
Normal life has been affected severely in Darjeeling and Kalimpong due to the ongoing indefinite shutdown.
Ethnic unrest in India's Darjeeling hills has wiped out the harvest of the world's most expensive tea, potentially pushing prices even higher.
The Gorkha Janamukti Morcha (GJM) today ruled out any discussion with West Bengal government but said it is "comfortable" in holding talks with the BJP-led government at the Centre.
The West Bengal government wrote to the Centre today seeking more forces to contain the current unrest in Darjeeling hills.
CM Mamata Banerjee told reporters in Kolkata that Assistant Commandant of the IRB's 2nd Battalion Kiran Tamang was critically injured in the violence.