Around 700 huts in a slum were reduced to ashes in an early morning blaze at Mahestala in West Bengal's South 24 Parganas district with local people alleging that the fire was deliberately started.
There was no casualty, fire brigade and police sources said.
Fire engines which arrived at the scene at 4:00am were hindered by railway lines beyond which the slum lay.
Train services on Majerhat–Budge Budge section was suspended from 04:50 am to 08:55am after which the fire brigade laid hosepipes over the railway lines to the slum, the sources said.
A total of fifteen fire engines brought the blaze under control, fire brigade sources said.
The sources said that around 700 huts were destroyed in the blaze rendering 3,500 people homeless.
Local people caught four persons and handed them over to the police alleging that the fire was their handiwork.
The police filed an FIR against eleven persons, including the Trinamool Congress councillor of Mahestala Municipality Dipika Dutta and TMC leader Rafiq Mollah.
Of the 11, five were arrested, police sources said.
The Chairman of the municipality Dulal Das who was away at Tripura for personal work denied the allegations of the local people and told PTI over phone that none from his party, the TMC, were involved.
Chief Minister Mamata Banerjee termed the fire as a 'small' one said "We will build houses for those whose homes were gutted in the fire."
She said that she had asked Fire Services minister Javed Khan to arrange for rehabilitation of the affected people.
Khan who visited the spot said that he had heard the complaints from the people and that he would submit a report to the chief minister.
Senior CPI(M) leader Surjyakanta Mishra, who is the Leader of the Opposition, demanded an inquiry into the cause of the fire.