Authorities on July 28 had detected the 400-m tunnel into India from Pakistan along Indo-Pak border in Samba district.
The tunnel was detected after an area caved-in in a straight line at two-three places due to rains near border fencing near Chillayari Border Out Post of BSF along the International Border in the Samba sector.
The tunnel at a depth of 25-ft has been dug out between two sides along IB on India's Chillayari BoP and Pakistan's Lumberiyal BoP. It had air supply through a two-inch pipe. The tunnel is 300-m up to border fencing and 100-m beyond the fencing into this side of the border.
"We have alerted those areas in particular which are sensitive in nature," Bansal said.
"Apparently when they could not succeed to breach the fence and security on the surface (for infiltration), they resorted to digging of the tunnel," he said. "We will find out the details as we explore the tunnel -- we will be able to draw our assessment and take adequate measures."
The BSF DG said, "We have lodged a protest with Pakistan during our meeting with them. And we have expressed concern that this appears to be an initiative that started across the border. This would be followed up subsequently after we have more details."
Replying to the question whether there is an involvement of the Pakistan army or its intelligence agency -- the Inter-Services Intelligence -- in the incident, the DG said, "There is no reason for me to draw conclusion. I will not hasten to reach any conclusion".
"We are trying to find out alignment and end of the tunnel -- once we have that, the conclusion will become obvious," he said.
Replying to the question about the preparedness of the BSF along the border, Bansal said his force is aware of its responsibilities. "Tunnelling is one of the standard methods of infiltration used worldwide -- therefore patrolling takes place every day and the security force keeps looking for signs of any digging of tunnel or breach of the fence and so on," he said.
The BSF DG said tunnelling is not a new method of infiltration along with border line, and his jawans are well aware of the fact.
Constructing a tunnel 20-ft below the ground needs the skills of a technical expert, he said."We are digging at various places which are actually the alignment of the tunnel. We have taken a decision now to dig in a particular manner which will be more helpful in finding the extent of the alignment," Bansal said.