Two light aircraft were flying low near the Ranbirsinghpora area of Jammu region where Border Security Force (BSF) has posts and their flight path was picked up by India's air defence units.

"Soon after, the Indian Air Force (IAF) alerted its air defence units and the Standard Operating Procedures (SOP) for air space violations were activated," IAF spokesperson Wing Commander T.K. Singha said.

The two olive-green aircraft with Pakistan Army insignia emblazoned on them, had come close to the border area for about a couple of minutes, which is a breach of bilaterally agreed norms on air space. The 198-km international border from Kathua bordering Punjab to Akhnoor north of Jammu is manned by the BSF. The Indian army is the second line of defence here.

“Yes, two light aircraft were sighted. Appropriate air defence procedures always follow whenever the situation warrants,” Singha said. The air defence SOPs could be a simple radio warning to the pilots of the aircraft violating the air space or it could be activating its air defence missiles and rockets to scrambling fighter aircraft from an air base nearby to chase them away and escorting the enemy aircraft to land on Indian soil.

Normally, the forces on the border are under instructions to shoot down any aircraft violating the air space, but before the troops could react, the aircraft flew black to the Pakistani side, officials said.

India has enough sensors along the borders to locate such air space violations, including ground-based radars, aerostat radars and the recently acquired airborne early warning and control system called as 'eye in the sky'.

According to the data provided to parliament in December last year, Pakistani military aircraft, helicopters and spy unmanned aerial vehicles have violated Indian airspace on 23 occasions last year.