The anger against the new waqf law singed Calcutta’s neighbourhood on Monday with Indian Secular Front supporters stoning police and torching their vehicles in Bhangar, South 24-Parganas.

Five police motorbikes and a prison van were destroyed and seven policemen were injured in the afternoon rampage at Sonpur market, about 30km from the city.

The police were trying to control a crowd of anti-Waqf Amendment Act protesters when they were targeted with a shower of stones from the streets and rooftops, officers said.

Tension had been brewing since morning, when busloads of ISF supporters were stopped from travelling to Calcutta to participate in an anti-waqf act rally from Sealdah.

Local sources said ISF chairman and Bhangar MLA Nawsad Siddique was to address the gathering at Sonpur market in the afternoon after returning from Calcutta. However, the situation went out of hand before his arrival.

“The crowd had gathered on the Basanti Highway, disrupting traffic movement, so we told them to clear the road. But they turned violent so fast that we had little time to react. They began hurling stones indiscriminately,” an injured police officer said.

The CRPF’s anti-riot specialists, the Rapid Action Force, were later deployed and dispersed the mob.

Some local people claimed the attack was a reaction to police “high-handedness”.

Siddique too accused the police of provoking ISF supporters by blocking their journey to Calcutta.

“On Sunday, state BJP leaders made provocative statements at a public meeting at College Square. But, surprisingly, the police didn’t intervene,” he said.

Siddique accused the ruling Trinamool of using the protests against the new waqf law to divert attention from the sacking of over 25,000 school staff. He blamed “goons planted by Trinamool” for the violence.

ISF sources claimed the Sonpur protest meeting had police permission. “Even then, the police began dispersing our men aggressively, creating tension,” an ISF leader said.

Sources said the police arrangement was insufficient to manage the large crowd.

Trinamool MLA Saokat Molla described the ISF as “a party of hooligans”.

“If they have so much anger against the new waqf law, why are they targeting Bengal police?” he said.

“They should have gone to Delhi to protest. But the ISF leadership will never do that since they have a clear nexus with the BJP.”

Molla announced a march to Sonpur on April 20 to protest the ISF’s actions.