A youth, said to be a member of a Naxalite outfit, has been arrested on charges of setting fire to a tram on College Street on Sunday night.

Bhola Dutta, in his early-30s, was picked up from his Muraripukur Road home on Monday. Police said he is a member of the Revolutionary Youth League (RYL), known to be sympathetic to the CPI (Maoist).

Sunday's incident marked the first attack on government property by Naxalites in Calcutta since the Seventies. In February, the window-panes of Lexus Motors, on AJC Bose Road, were smashed by a group of Jadavpur University students who were reportedly members of a Naxalite group. Three of them were arrested.

An RYL spokesman said "last night's incident was a symbol of our protest against the state government's atrocities in the name of industrialisation", but the police dubbed it a "criminal" act.

"We are not ready to accept the RYL's claim that setting ablaze the tram was part of their political movement. The incident was a criminal act and the accused will be treated accordingly," said Pradip Chatterjee, deputy commissioner of police (headquarters).

Dutta, who runs a small business, has been charged with damaging government property and indulging in criminal conspiracy. Chatterjee said all those present with Dutta have been identified. "We will arrest them soon."

A group of five intercepted the tram heading towards Belgachhia at the crossing of Mahatma Gandhi Road and College Street. "After the driver and the passengers in the first-class coach were forced to get off, the youth sprinkled kerosene on the footboard and threw a burning matchstick," said an officer of Bowbazar thana.

On seeing a police jeep, the youths fled, leaving behind handwritten leaflets. "The fire was doused immediately and the tram taken to the depot," said the officer.

The RYL spokesman asserted that such incidents would recur if the government did not adopt "a people-friendly industrialisation policy".