Sikh extremists fatally shot four Indian soldiers and used a bomb to derail an army train transporting troops and tanks to the Pakistani border, police in Punjab state said Wednesday.

At least 18 other soldiers were wounded when Sikh gunmen fired on the train Tuesday night, one police official said. Other officials said up to 60 men were hurt, mostly in the derailment and not from bullets.There were conflicting reports on how the deaths occurred in the attack near the Pakistani border, 50 miles southeast of Amritsar and 185 miles northwest of New Delhi.

The most senior civil servant in the area, Firozpur Deputy Commissioner Suresh Kumar, said the four soldiers were crushed under tanks toppling off the derailed cars.