Defence Minster Manohar Parrikar on Wednesday said the land mines being blamed for the Pulgaon depot blaze in Maharashtra might have been faulty because DRDO did not do "hand-holding" for the production agency, Ordnance Factory Board (OFB).The Defence Minister was speaking at an event to hand over the indigenous heavy weight torpedo Varunastra to the Indian Navy.The minister told the Defence Research and Development Organisation (DRDO) to do 'hand-holding' for production agency Bharat Dynamics Limited (BDL) for the torpedo."The anti-tank mine which has been in discussion because of Pulgaon explosion... probably that product did not go as expected because DRDO did not handhold the production agency OFB until they were quite comfortable and sure," Parrikar said.The documents submitted to the court of inquiry for the blast suggest defective anti-tank mines, packed with poor quality explosives, could have been the cause of the disaster.A massive fire and explosion at India's largest ammunition depot in Pulgaon, in Maharashtra's Wardha district, on May 31 killed 19, including two officers.