Chandigarh, July 30 : With drug trafficking posing a threat to society, the Centre has adopted a zero tolerance policy towards narcotics and it is showing results, Union Home Minister Amit Shah said in Chandigarh on Saturday. Shah was in Chandigarh, his second visit to the city within four months, to inaugurate the two-day Narcotics Control Bureau (NCB) national conference on drug trafficking and national security at Punjab Raj Bhavan. He will also inaugurate several developmental projects. Under the virtual watch of the Home Minister, more than 30,000 kg of seized drugs was destroyed by the NCB, which started the drug disposal campaign from June 1 and over 51,217 kg of narcotics have been disposed of in 11 states till July 29. On the call of Prime Minister Narendra Modi to celebrate 'Azadi ka Amrit Mahotsav', the NCB took a pledge to destroy 75,000 kg of drugs on 75 years of independence. Shah in the evening will attend the "Har Ghar Tiranga" and "Azadi Ka Amrit Mahotsav" laser show at the famed rain-fed Sukhna Lake. On reaching the Chandigarh airport, which was delayed by some hours, he was received by Punjab Governor Banwarilal Purohit, Haryana Chief Minister Manohar Lal Khattar, Haryana Home Minister Anil Vij, Chandigarh MP Kirron Kher and Chandigarh Adviser Dharam Pal. /IANS