Fifteen people, including six BJP councillors and two former MLAs, were later arrested and charged with rioting, obstructing a public servant on duty and holding a demonstration without prior permission.

Trouble began this morning when over Sangh activists marched up to A K Gopalan Bhawan — the CPM headquarters in Gole Market — where a meeting of the party central committee was on. “At around 11 am, when we took a break for tea, we realised that a few RSS protestors were forcing their way into our office. The police were unable to stop them. When we tried to reason with them, they started pelting stones,” said Hari Singh Kang, a CPM central committee member who was among the injured.

The BJP and RSS members, on the other hand, claimed they were leading a peaceful protest over seven deaths in Kannur in Kerala. They alleged that the CPM began the stone-pelting.

“We were in a peaceful protest and before we knew it, Left party members were pelting stones at us from the first floor of their office. I tried to stop our party workers from retaliating when a big stone hit me in the head,” said Moolchand Chawla of the BJP. “They provoked us into retaliating but we remained peaceful,” he said.

The AKG Bhawan became a battleground as stones flew in all directions. Window panes of the building were shattered and cars parked outside were damaged, among them those of CPM general secretary Prakash Karat and politburo member Sitaram Yechury.

Karat condemned the attack. “RSS members came to demonstrate yesterday as well but they were stopped by the police at Pandit Pant Marg. Despite informing the police about the situation, there were only two officers stationed here in the morning. Everyone knows that the BJP and the CPM have a number of political differences but it is highly condemnable that they should resort to such violence,” he said.

He said that known BJP and RSS leaders led the protest and that the CPM had mentioned their names in the FIRs — the party has accused Delhi Opposition leader Jagdish Mukhi and Mayor Aarti Mehra of leading the attack.

“There is a problem in Kerala and it’s not new. Four of our members were murdered by the RSS but we did not retaliate with violence,” Karat said, adding there was no justification for this “premeditated attack”. “We will be asking other parties to condemn this action and many have already come forward to our support. Public opinion will definitely be against the BJP.”

Meanwhile, the RSS said the CPM should not expect it to take the violence “lying down” and the BJP youth wing has called for a nationwide protest on Monday. The BJP said it would raise the matter in Parliament.

“Our workers were attacked and around 15 activists were injured when stones were pelted on them from inside the Marxist party office,” said BJP leader V K Malhotra. “We condemn the murder culture of the CPM. They have done it in Nandigram and have been doing it for several years in Kerala,” he said.

RSS spokesperson Ram Madhav spoke on similar lines. “When our members were peacefully demonstrating outside the Marxist party office, Marxist elements displayed their fascist violent attitude like in Nandigram and Kannur,” he said.

Madhav said that in the last five days “Marxist goonda elements” have been resorting to “barbarous violence” in Kannur, killing five BJP-RSS activists and seriously injuring dozens of workers.

“The RSS cannot be cowed down by violence. We will take it head-on. We only want to ask the Kerala government to take immediate steps to restore peace. Don’t expect us to take it lying down,” he said.

BOX: They knew, says VS, points finger at BJP leaders

KOCHI: Kerala Chief Minister V S Achuthanandan said it was no coincidence that the CPM office in Delhi was stoned the day after BJP vice-president Venkaiah Naidu declared his party’s intentions in Kochi. On Saturday, Naidu had said it would look “very pathetic” if the BJP decided to do in its strongholds what the CPM was doing to the BJP-RSS in Kannur. The CM alleged that the BJP national leadership was in full know of the “attack” plans.