Kolkata, March 6 : Three minor boys were killed in a landslide in West Bengal's Darjeeling district on Monday morning while they were indulging in illegal sand mining. The bodies of the three -- Manu Kumar (16), Shyamal Sahani (15) and Rohit Chauhan (15) -- have been recovered from the riverbed. Initial investigation suggested that they were probably engaged in their assignments of sand and stone mining at Balason riverbed on early Monday morning, when landslides happened killing them. According to district police officials, a fourth minor boy, who was injured severely, has been admitted to the North Bengal Medical College & Hospital at Siliguri by the police. Local residents detected the bodies and they informed the local police. The police removed the soil through earthmover and recovered three bodies and shifted the severely injured to hospital. The local people have alleged that illegal sand and stone mining at the Balason riverbed by the mafias had been rampant for some time and in that process the operators mainly use child labourers like the victims against some paltry payments. The local people also alleged that although the police are aware of this menace no strong action had been initiated so far. The family members of the victims have alleged that one Ganesh Sardar, a local middleman, is mainly responsible for the supply of child labourers to the illegal sand and stone mining mafias. Sardar is absconding. /IANS