Shailendra Lal said the tractor was crossing the railroad track near the town of Bijnor in Uttar Pradesh state when it was hit by the passenger train late Tuesday.
Lal said the wagon was overcrowded with people returning from a ceremony at a nearby Hindu holy town near the Ganges River.
Railway accidents are common in India, which has one of the world's largest train networks serving about 23 million passengers a day.
A lack of money means that hundreds of dangerous crossings in the country are not guarded around the clock.
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