Kolkata, May 25 (IANS): Even before the state BJP's march to the city police headquarters formally started, a group of its party workers on Thursday surprised the police by suddenly arriving near Lalbazar in a private bus.

Around 20 Bharatiya Janata Party activists from Nadia district's Haringhata, travelling in a private bus, reached the Bipin Behari Ganguly street crossing near the city police headquarters Lalbazar.

However, they were immediately intercepted and detained by the police personnel posted there.

Lalbazar, situated in central Kolkata, was turned into a fortress since the morning. A huge number of police personnel were deployed near three major interception points at Phears lane, Tea Board of India office and Bentinck Street connector to stop the BJP rallies.

Barricades, guard rails, and around 200 heavily armed personnel including combat forces, Rapid Action Force and commandos have been deployed to check any untoward incidents.

The protest, coming only three days after the Left peasant unions' "March to Nabanna (state secretariat") that left nearly 200 injured following trouble, has kept the police on its toes

Leading a massive rally of around 20,000 activists from Howrah station, BJP state president Dilip Ghosh said they would start sit-in protests on the street if the party workers are stopped anywhere by the police.

"Our aim is to reach Lalbazar. If police stop us anywhere, we would start sit-in demonstration on the spot. Police would do their job and our party workers would do theirs," Ghosh said.

"We want to tell the administration that their brutality, torture and intimidation would not be tolerated anymore," he added.

Protesting the law and order situation in the state and fake cases lodged against their party workers among other issues, the state unit of BJP has promised to rally around one lakh people to the city police headquarters Lalbazar on Thursday.