India, May 14 -- A motorcycle was burnt, stones thrown and a bust of social reformer Iswar Chandra Vidyasagar vandalized during BJP chief Amit Shah's mega roadshow in Kolkata on Tuesday evening. The BJP and Bengal's ruling Trinamool Congress have accused each other for violence at two places.

The violence triggered a sharp reaction from Bengal Chief Minister Mamata Banerjee who appealed for calm but pinned the blame for the violence on BJP supporters.

"We apologise for their acts... Why did the police allow them to hold the roadshow?" Banerjee said at a public meeting in south Kolkata's Behala area minutes after the first reports of the violence came in.

Banerjee also warned that if its leaders ended up hurting Bengal's heritage, "no o...