Kolkata, Nov 22 : At least three children were injured in a crude bomb blast in West Bengal's Murshidabad district on Wednesday. The incident took place in Imamnagar under the Farakka police station limits. According to police sources, the children -- Ehdina Parvin, Mehmuda Khatun and Wasim Sheikh -- received severe burn injuries and have been admitted at the nearby Jangipur Hospital. Their condition is said to be critical, the sources added. As per locals in the area, the crude bomb exploded when the children were playing with it, mistaking it with a ball. A huge police contingent has reached the spot and has initiated a probe into the incident that has led to tensions in the area. This is second such incident in more than a month. On October 6, five children were injured after a crude bomb exploded in Duttapukur, North 24 Parganas district. The children found a number of crude bombs and mistaking them for balls, they started playing with one which went on to explode. /IANS