CPI(M), BJP and Congress on Friday joined in a chorus to flay the Mamata Banerjee government for setting a "dangerous trend of silencing cartoonists" by arresting them for criticising political leaders.

Expressing surprise at the arrest of a professor of Jadavpur University for allegedly posting cartoons on a social networking site, leader of opposition Suryakanta Mishra said, "It shows lack of patience of the state government which has poor knowledge that everyone has the right of expression."

The CPI(M) leader described the police action as "unprecedented".

BJP state president Rahul Sinha said there had been "dangerous cartoons" in the past against Indira Gandhi, Atal Behari Vajpayee, LK Advani, Jyoti Basu and others "but no political party took any action against any cartoonist."

"Are we really heading for a party-sponsored emergency?" Sinha said.

A leader of TMC ally, Congress' Om Prakash Mishra dubbed the arrest as "unfortunate".