Four persons were killed and 12 others were injured when a bus collided with a mahindra in Rajoir upazila of Madaripur district on Friday.The accident took place at Kalibari area on Dhaka-Barisal highway around 12:15pm.Confirming the matter Md Kamrul Hassan, officer-in-charge of Rajoir Police Station said two people were died on the spot and two others were succumbed to injuries on their way to hospital.