The Border Security Force (BSF) has launched a massiveoperation along the 180-km International Border (IB) with Pakistan to detectunderground, cross-border tunnels in view of possible infiltration attempts byarmed terrorists into Jammu and Kashmir, officials said on Thursday.Armed withmodern tools and equipment, BSF personnel began the operation with clearingbushes and digging and tilling the land close to the three-tier border fencingup to the Zero Line with Pakistan."The exercise has been launched alongthe IB in the Jammu frontier area to detect cross-border, undergroundtunnel," a senior BSF officer said.The officials said the troops had beenasked to dig anti-tunnelling trenches of a particular depth along the borderfencing in Jammu, Samba and Kathua.

The operation was initiated earlier this week following thearrest of a Pakistani youth from a village in the R S Pura sector in Jammu.Theyouth, Mohmmad Amin, crossed the International Border and managed to reach thevillage last week even though there was no breach of fencing, raisingapprehension about cross-border tunnels, they said.

In some places, Pakistani troops tried to disrupt theprocess by resorting to firing, they said.As a counter-infiltration measure,the BSF has also activated its ground sensors to detect underground tunnels.

The BSF launched a mega exercise to fortify the"anti-infiltration grid" along the border with Pakistan in Punjab andJammu in July this year, and mobilised its entire senior field brass, thousandsof troops and machinery.The operation, code named 'Sudarshan', was launched onJuly 1 and will cover the entire International Border with Pakistan stretchingover 1,000 kms.

The BSF and Army troops have detected six cross-bordertunnels along the border in Jammu region since 2012. These were used to pushPakistani terrorists into Jammu and Kashmir, they said.

Earlier this week, Army Chief General Bipin Rawat saidPakistan has reactivated the Balakot terror camp very recently and about 500infiltrators were waiting to sneak into India.

Balakot had suffered damaged and was destroyed by thecross-border strike by the Indian Air Force in February. "That is whypeople have got away from there and now it has been reactivated," the Armychief said in Chennai on Monday.