Sources said the opening of the tunnel was found near Regal area of Samba sector where there is thick undergrowth and bushes.
The firing from across the border in Satpal, Manyari, Karol Krishna and Gurnam border outpost areas started around 9 pm on Saturday, drawing strong and effective retaliation from the BSF.
In the exchange of fire, which continued till this morning, one woman suffered injuries at Manyari village, they said.
Border residents said Pakistani Rangers have been targeting civilian areas during the night.
Officials said the Pakistani Rangers started the firing around 9.50 pm on Monday and targeted BoPs and villages in the Pansar-Manyari belt of Hiranagar sector.
The official also said Pakistani rangers targeted forward areas along the IB in Hiranagar sector of Kathua district and they kept firing intermittently for five hours.
The farmers were provided tractors with Bullet Proof (BP)-shields keeping in mind ceasefire violations.
The BSF opened fire and foiled their attempt, the official said.
Over 8,000 acres of land across the fencing, spread across 22 border villages from Paharpur to Londi in Hiranagar sector, is lying unattended by border residents.
The terrorists fled back to the Pakistani side after being confronted by the border guarding force, the spokesman said.
The Border Security Force recovered a gun and an undisclosed amount of heroin from the intruders after the incident in Gajsinghpur sector.
The man was killed by a BSF party near the Gopalpur post of the border force in Malda district of the state on Saturday evening.
Meanwhile, the Border Security Force shot dead five intruders along the India-Pakistan International Border in Punjab early Saturday, a senior BSF officer said.
Local police are investigating the matter and the bodies have been recovered from the farmlands close to the IB.
Sources said that the unprovoked ceasefire violations are in contravention of the 2003 ceasefire understanding between the two countries.