(From left) The crowd that laid siege to Kiron Shankar Roy Road (picture by Sanat Kumar Sinha), the taxi driver who tried to park on the wrong side and the constable who assaulted him (Telegraph pictures)

A traffic constable punched a taxi driver over a parking violation and Calcutta found another reason to lapse into lawlessness in full view of the high court.

Kiron Shankar Roy Road turned into rowdy road for four hours on Tuesday, with a mob taking on the police after traffic constable Nepal Chandra Banerjee assaulted taxi driver Munmun Yadav for trying to park on the wrong side.

The police later lathicharged the protesters, including some high court lawyers, to “rescue” Banerjee from the pharmacy in which he was being held hostage. By evening, Mamata Banerjee was in the fray, leading the campaign for the constable’s arrest and demanding an official apology for “police high-handedness”.

The Trinamul Congress leader threatened a repeat of Friday night’s Bondel Road blockade over police action on the auto brigade if Banerjee wasn’t arrested.

The fracas began at 2.30pm, when 37-year-old Yadav was about to park his vehicle on the wrong side of Kiron Shankar Roy Road. Banerjee, who was on duty in front of the high court, spotted the taxi and signalled to the driver to stop. When he didn’t, the constable sprinted towards the taxi, witnesses said.

“He was holding an iron clamp, which he tried to attach to one of the wheels to prevent the driver from fleeing. The driver alighted and asked Banerjee why he was using the clamp instead of filing a case of parking violation,” a bystander said.

Banerjee allegedly replied with a slap. “The cop caught the driver by his collar, dragged him to the middle of the road and hit him. One of the blows landed on his eye. I was shocked to see a policeman beat up someone like this,” said Tapas Halder, who had just got off Yadav’s taxi.

Halder and some witnesses sided with Yadav and forced the constable to take him to a nearby pharmacy, Keshwani Medical Stores, for first-aid. A crowd had gathered outside the pharmacy by then and the protesters demanded that Banerjee, who is attached to the Headquarters Traffic Guard, come out and face them.

Halder left after arranging for a taxi to take Yadav to Medical College and Hospital. That was before a police team led by deputy commissioner (traffic) Dilip Banerjee arrived. “The deputy commissioner ordered a lathicharge instead of giving us a hearing. Some of us were beaten up. The police team then escorted the constable to a jeep that took him away,” high court employee Pankaj Mondal said.

With more people joining the protest and traffic coming to a standstill, additional forces were called in. Trinamul leader Madan Mitra arrived soon after and fuelled the unrest. The Trinamul brigade asked Damayanti Sen, the deputy commissioner of police (central), to apologise to the crowd and order the constable’s arrest.

Mamata arrived midway through the “negotiations”. After a briefing by her brood, she grabbed a handheld microphone and demanded that the police take action against the constable, apologise for beating up lawyers and others and compensate the taxi driver.

“Our party will take care of the driver’s medical needs and pay Rs 50,000 as relief,” she said. Yadav had by then been discharged from hospital following first-aid.

The Trinamul-led blockade was withdrawn only after Sen apologised.

Pradip Chattopadhayay, the joint commissioner of police (administration), said a preliminary probe revealed that the constable was not at fault.