A thick film of oil spreads on the waters in the Hooghly after a collision between cargo ships at Nurpur in South 24 Parganas district on Tuesday. NURPUR (SOUTH 24 PARGANAS DISTRICT): A cargo vessel on its way to the Kolkata port rammed another such ship bound for Colombo on the Hooghly river here on Tuesday. Though none of the crew was injured, both vessels suffered extensive damage and a large quantity of oil spilled into the river as a result of the collision. Registered in Bahamas, Green Valley collided with Tiger Spring