Claiming that the attack was “unprovoked and pre-planned”, a statement released by the party said a number of CPM activists, including two central committee members, were injured in the incident.

Bose said that party workers have been asked to bring out protest rallies all over the state on Sunday.

The party will take out rallies again on Monday against the attack.

“Those units which could not bring out the rally today will do so tomorrow,” said CPM state committee secretary Biman Bose said.

Launching a scathing attack on the VHP and the RSS, Bose said, “It was a dastardly act committed by the VHP and RSS and the parties will face the challenge politically.”

“In 1959, during the food riots, scores of our supporters were killed by the police. But we did not ransack the Congress Bhavan at Chowringhee Road, as we do not believe in the culture of vandalism and destruction,” he said.

The secretary further said, “When the RSS was set up in 1925, they had Hiltler as their icon. No wonder they had behaved the way they did today,” he added.

Bose was also critical of the role played by the Delhi Police in handling the situation.

“Had the police been more active, there would have been less damage to property,” he alleged.

Pointing out that Delhi Chief Minister Sheila Dikshit and some senior Congress leaders had visited A K Gopalan Bhavan after the attack, Bose said Samajwadi Party chief Mulayam Singh Yadav and TDP leader Chandrababu Naidu had also condemned the attack.

“It is good to see that the attack had been condemned by most political parties. The Left and democratic parties should unite in their protest against the attack,” he added.