Kolkata - Indian police have arrested four suspected corpse smugglers and recovered 18 intact skeletons and other bones believed exhumed from cemeteries in a notorious grave-robbing district.An official said on Tuesday that police seized the "neatly washed and cleaned" human remains from a village in West Bengal state's Burdwan district that led to the arrest of four men allegedly part of an international smuggling ring. Anuj Sharma, West Bengal's deputy police chief, said the skeletons were about to be smuggled and sold. We suspect that they are part of an international skeleton smuggling racket".Sharma said the recovery was part of a larger consignment that was being smuggled out of the area. Investigators have identified the recipients of the cache that they suspect was stolen from graveyards in the Muslim dominated district. Burial costsViolence broke out in the village in 2006 over the security of graveyards after police seized more than 20 human skulls, with locals demanding armed guards to protect the burial sites. A year later 50 skulls were recovered from the same district.India banned the trade of human bones in 1985 after coming under pressure from human rights groups that argued the practice violated the basic principles of humanity, but it simultaneously forced the trade underground.Before the ban, many poor families were selling the corpses to smugglers to save on cremation or burials costs in the poverty-stricken region. Local gangs steal corpses from burning pyres and graves, with many relying on morgues that sell them unclaimed bodies for few thousands rupees.