The tunnel was found at Munawar Tawi in Akhnoor. The police said there was no clarity over where the tunnel originated from.
Defence Minister Arun Jaitley on Tuesday had raised the issue of violations in Parliament.
All four injured belong to the Gorkha regiment of the Army.
<p>Forty-five pouches and 30 bottles of liquor, to be sold illegally, were seized in Jammu region's Akhnoor belt and two persons were arrested in this connection, police said on Sunday.</p>
There has been continuous firing since Thursday night by the Pakistani forces along the LoC at RS Pura, Akhnoor and Hiranagar sectors.
Pakistani troops fired at Indian positions in Akhnoor sector along the Line of Control (LoC) in Jammu and Kashmir late Monday, an army spokesman said on Tuesday.
A Rashtriya Rifles personnel, who was on leave, was found with both eyes severely damaged. Rajesh Kumar Dutt was brought to the government hospital after he was rescued from Akhnoor in a serious state.
The Army said it could not interrogate jawan Rajesh Dutt because of the condition he was in.
The Dalai Lama will also address a gathering of school children in Akhnoor on Wednesday.
Eight years after the Kargil war, farmers in border sector of Akhnoor, J&K, are returning to their demined fields.
Maximum Cases, Maximum Deaths: Maharashtra Scrambles to Fight Challenges as Covid-19 Spreads
A 'Green' Lining? Coronavirus Could Trigger Biggest Fall in Carbon Emissions Since World War Two
Odisha: 48-hr ‘Complete Shutdown’ in Cuttack, Bhadrak & Bhubaneswar as Covid-19 Tightens Grip
‘Woman in Labour Turned Away’: Posh Colonies Near Nizamuddin Close Doors on Locals