Bengal's Opposition parties on Tuesday hit the streets demanding the arrests of the accused Trinamul leaders and the release of innocent protesters.

Basirhat, the subdivisional headquarters of North 24-Parganas district, looked like a fortress on Tuesday with police setting up checkpoints at several entry points to the town to thwart back-to-back agitations of the BJP, the the CPM and the Congress. Layers of barricades were put up to prevent protesters from reaching the office of the superintendent of police. The police also clamped prohibitory measures, including Section 144, on a 500m radius from the SP's office.

While the police managed to prevent Congress supporters well ahead of the town at Nazat, cops had a tough time handling the BJP protest led by state unit president Sukanta Majumdar, who arrived in the town by a local train and reached the agitation spot riding a bike. Aggressive BJP supporters broke barricades and allegedly pelted stones. The police lathicharged the crowd. Then, angry BJP supporters, along with Majumdar, began a demonstration by lying down on the Ghojadanga road.

Majumdar said: "The police instigated violence allowing goons to hurl stones from the adjacent rooftops. We apprehended this attack and told the SP to take preventive action. But he did not respond, rather unleashed terror by lathicharging inhumanly, which injured many party workers."

Police sources said 15 persons were detained for attacking the police.

The CPM also held a demonstration demanding the unconditional release of former party MLA Nirapada Sardar. Sardar was arrested last week for allegedly instigating villagers, especially women, against local Trinamul leaders.

Although the CPM demonstration in Basirhat was largely peaceful, at least 12 persons, including policemen and CPM workers, were injured in a clash in Murshidabad's Behrampore on Tuesday when over 5,000 people led by senior CPM leaders attempted to enter the district magistrate's office as part of its statewide political activity centred around Sandeshkhali and Sardar's arrest.

A source said the clash broke out when the CPM workers surrounded the police who put up barricades to stop the crowd from moving toward the district magistrate's office.

"Police failed to manage the mob. They were surrounded by the CPM workers. As police resorted to lathi-charge and fired teargas shells, CPM workers retaliated with stones and brickbats," said the source.

CPM state secretary Md Salim was in Behrampore to address party workers before they marched towards the DM office.

A police officer said six cops, including Lalgola officer-in-charge Supriyo Ranjan Majhi, were injured by brickbats. Majhi and a sub-inspector have been hospitalised with head injuries.

CPM's Murshidabad district committee secretary Jamir Mollah claimed six of his party colleagues were seriously injured and at least 50 suffered minor injuries in the police attack.

While Sandeshkhali remained out of bounds for Opposition parties, on Tuesday evening a Trinamul delegation led by Naihati MLA and irrigation minister Partha Bhowmik reached Kalinagar under Sandeshkhali block-1. The team held talks with the police and party leaders. Bhowmik announced a public meeting in Sandeshkhali on February 18.

"Women are the source of our power. Our chief minister is a woman who never allows any atrocity on women. This is Bengal, not UP where women are set on fire after rape.... Our prime objective is to ensure the safety and security of dignity of women," Bhowmik said.

Trinamul insiders said senior leaders were told how the mass agitation against some Trinamul leadership unfolded and embarrassed the party.

"There were some faults on the part of some of our leaders, but the CPM and the BJP conspired to escalate (people's anger) for vested political interest, which we won't tolerate," a Trinamul leader said.

Trinamul's Uttam Sardar and BJP's Bikash Sinha, who were re-arrested on Monday soon after they were granted bail, were produced in the ACJM court, Basirhat, on Tuesday. Both were remanded in police custody for four days. Police sources said Uttam was arrested in an alleged case of molestation, threat and intimidation, and Bikash for fomenting tension.

Basirhat ACJM court lawyers also protested on Tuesday against the arrest of one of their colleagues who was part of the BJP legal team and alleged that the police misbehaved with a woman lawyer on Monday when Uttam and Bikash were being re-arrested.