Chinese troops are reported to have entered 25 to 30 km deep into Indian territory in Burtse area in Ladakh where they had pitched their tents last year that had led to a tense three-week standoff.
The Burtse area of North Ladakh in Jammu and Kashmir is at an altitude of 17,000 feet.
Indian troops noticed the People's Liberation Army (PLA) personnel yesterday while moving from their base towards the higher 'New Patrol base' post in the Burtse area.
Reports quoting sources said the Chinese were spotted in Indian territory 25 to 30 km from the perceived Line of Actual Control (LAC).
Indian troops returned back to their base camp as per the newly drafted Standard Operating Procedures, but the Chinese personnel stayed on and were at the spot when Indian troops went on a patrol again to the 'New Patrol base' post in the wee hours of Monday.
The PLA personnel were still sitting on the ground with flags reading "this is Chinese territory, go back" in their hands.
Although the Indian side had a Quick Reaction Team accompanying them, nothing could be achieved as the PLA personnel refused to budge and the Indian troops returned to their base and informed their higher ups.
Col S D Goswami, an Army spokesperson based in Udhampur, has reportedly denied any such incident had taken place, but said there was no commonly delineated LAC between India and China which led to transgressions.
The Army and India's defence authorities usually refer to such Chinese border violations as differing perception of LAC. They say transgressions occur as both sides undertake patrolling up to their respective perception of the LAC.
He said India regularly takes up any transgression by the Chinese side through established mechanisms such as flag meetings, border personnel meetings and normal diplomatic channels like Working Mechanism on Consultation and Coordination on India-China Border Affairs and the issues are sorted out through the provisions of various agreements between India and China.
The Indian border patrol also is reported to have made a vain attempt to reach the 'New Patrol Base' from a place known as 'Nallah one', near its base.
A satellite image of the area is likely to be taken to ascertain whether the Chinese PLA have pitched in tents like it did last year, the sources said, hinting at the possibility of some tents being erected by the Chinese troops to facilitate their movement deep into the Indian territory.
The Burtse area, which is adjacent to Daulat Beg Oldie (DBO), forms part of huge Depsang plains perceived by India as its own territory. However, the Chinese side has been claiming it to be part of their territory as it gives them a tactical edge over the area, including the air field which was operationalised by the Indian Air Force last year for a brief while.