In Bengal, her party workers exacted revenge today, vandalising Left offices in different parts of the state. In Siliguri, Ms Banerjee's Trinamool Congress attacked the CPM office with stones. But the police chose to arrest around 25 CPM leaders on charges of "instigating" the violence.
A CPM rally with nearly 10,000 people had ended peacefully when Trinamool cadres crossing the Left office started hurling bricks. The Left reportedly retaliated. The police used batons on the demonstrators but after a Trinamool minister arrived and blamed the Left, the police entered the Left office and arrested two senior leaders including a former minister.
Ms Banerjee is in a nursing home in Kolkata. On Facebook, she posted, "Politics has become so dirty and nasty. I have spent about 25 years in Delhi since my election as Member of Parliament in 1984. What I saw yesterday is totally unprecedented and I have no words to express my condemnation of this incident. I am really shocked."
She has been unwell since she was heckled last evening by student activists as she arrived at the Planning Commission.
West Bengal's Finance Minister Amit Mitra, who was accompanying her, was physically abused by members of the CPI(M)'s youth wing, the Students Federation of India (SFI). They blame the government for the death of a 22-year-old colleague in police custody.
This morning, Ms Banerjee denied that Trinamool workers were taking punitive action against the Left. "My party workers are passionate, but they listen to me. They will not indulge in violence when I have told them not to," she said before boarding a private plane for Kolkata.