By Subir Bhaumik
BBC correspondent in Calcutta
Indian officials say the West Bengal state government has failed to utilise much of the federal funds given for modernising its police force.
The police force needs modern equipment and training
A home ministry official said the state police remained inadequately equipped to face rebel groups and tribal insurgents in its northern districts.
But state police officials blame the late release of funds by the West Bengal finance ministry for the failure in spending.
The home ministry official, unwilling to be named, said West Bengal had received more than 1,200 million rupees ($25m) since 2001 to modernise its police force.
He said only 40% of that money has so far been spent on modern weapons, equipment, training and for expanding the police network.
The official said his ministry had repeatedly asked the state government to spend the money appropriately since the increased threat of militant strikes, after last year's attack on the US
Bengal was also facing a separatist insurgency by Kamtapuri tribesmen in its northern districts bordering Bhutan and the state of Assam.
West Bengal police officials admitted that much of the funds earmarked for police modernisation could not be spent.
They say it is important to spend on modern weapons and training, communication equipment and police housing and for setting up new police stations.
They say that late release of funds by the state's finance ministry was "the main reason" for the delay in spending.
Security analysts say Bengal police urgently needs to raise a special force to handle future attacks.
They say its armed police units are too poorly trained to handle such situations .
They are still equipped with the World War II vintage rifles considered a liability in close quarter combat with terrorists.
During this year's Tripura state elections, a Bengal police contingent deployed there refused to go on long patrol in the hills .