The BJP leadership blamed the state's ruling Trinamool Congress, but the latter denied it and alleged that Basu's car was attacked by locals after he made provocative comments.
The incident took place after Basu emerged from the Bhupatinagar police station where he filed a complaint against attacks allegedly carried out by Trinamool Congress activists against his party functionaries in the area.
As the convoy started moving, a mob attacked it with sticks and stones.
"They started throwing stones indiscriminately, and hit the cars in the convoy with sticks. Our workers were escorting my car on motor cycles. They were dragged from their vehicle and beaten up. What was most surprising, the police escorts given to me remained silent spectators throughout the incident," he said.
Talking to , Basu said all the cars in the convoy were attacked. "As they rained blows with sticks and threw stones, the window panes of my car were smashed. I got wounds from the shards".
Later, BJP supporters put up a road blockade at Heria in the district. "They are demonstrating everywhere," said Basu, who continued his tour despite the attacks.
The BJP state leadership condemned the "brutal attack" on Basu by "Trinamool goons".
"In today's Bengal, none of the oppsotiion leaders is safe as they are being attacked, tortured and humiliated by the adminsitraiton and the Trinamool goons," state general secretary Raju Banerjee said in a statement.
( With inputs from IANS )