Yogesh Varshney of the Bharatiya Janata Yuva Morcha made the statement after police clashed with people taking part in a Hanuman Jayanti rally in West Bengal's Birbhum district.
"She stands up for Muslims. Aren't Hindus human beings? If there was some humanity, then there wouldn't be so much discrimination against the Hindus," he said after apparently seeing a video of police assaulting the rallyists to disperse them.
"There is only one thought that crossed my mind after watching that video... Whoever will cut off Mamata Banerjee's head, I will give that person Rs 11 lakh as reward," Varshney said.
Varshney's Rs 11-lakh offer went viral on social media, triggering outrage.
Describing the comments as provocation against a popular Chief Minister and attack on women, opposition leaders vehemently condemned the incident in both houses of Parliament.
Terming the comments by Varshney as "jihadi-like", BJP's National Secretary Rahul Sinha said that in Kolkata such comments would not get any support.
"We doubt if he has the credibility to be a BJP Yuva Morcha leader. Such comments cannot be supported by anyone.
He has made a most jihadi-like statement," Sinha said.
"We will continue to oppose Mamata Banerjee on political grounds. But BJP does not approve the politics of hatred and murder, though such extreme comments were made by Trinamool Congress leaders earlier," he said.
Taking a swipe at the BJP leader for his comments, Trinamool Secretary General Partha Chatterjee said they had no idea what Banerjee had gone through in her political career and what she was made of.
"These leaders sitting in different states have no idea what she is made of. She has faced physical assaults several times earlier in her political career.
"She was thrown out of the Kolkata police headquarters in Lalbazar and dragged out of the Writers' Building (the state's permanent secretariat) during the CPI-M regime. Police dragged her by the hair from Singur during the land movement (in 2006) but nothing could stop her," Chatterjee said.
Varshney's comments came a day after rallyists carrying saffron flags were stopped by police and Rapid Action Force in Suri in West Bengal's Birbhum district, sparking trouble.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)