NEW DELHI: People’s liberation army troops of China violated the new border defence cooperation agreement (BDCA) by tailing Indian soldiers in eastern Ladakh in June, which led India to lodge a formal protest with China last month.The BDCA, inked between India and China on October 23 last year, prohibits either side from tailing each other’s patrol in areas where there is “no common understanding” and dispute over where the line of actual control (LAC) actually lies. The “no tailing” clause is significant because a patrol following a rival patrol often triggers tensions and face-offs in the disputed areas.“Since signing of the BDCA, Chinese troops have on one occasion violated the provision by tailing our patrol in eastern Ladakh on June 2. A protest was lodged against this violation in the flag meeting held on July 15,” said defence minister Arun Jaitley , in Lok Sabha on Friday.Both Indian and Chinese armies for long have been patrolling aggressively along the un-delineated 4,057-km long LAC, stretching from Ladakh to Arunachal Pradesh, to strengthen their claims on disputed areas. But unlike the volatile Line of Control (LoC) with Pakistan, where cross-border firing is frequent and leads to casualties on both sides, no fire has been exchanged across the LAC for decades.Defence minister Arun JaitleyThe “unusual” 21-day face-off in April-May last year after PLA troops intruded 19km into Depsang valley in DBO sector of eastern Ladakh had, however, had come as a big shocker for India. After taking military and diplomatic steps to force the Chinese troops to withdraw, India had then begun to push for “greater predictability and stability” in tackling such incidents through the BDCA.It basically consolidates earlier such pacts inked in 1993, 1996 and 2005 to strengthen various de-escalatory steps while reaffirming that “neither side shall use force or threaten to use force” or “seek unilateral superiority” to alter the status-quo along the LAC.“The BDCA provides a more vigorous protocol to defuse troop face-offs and transgressions, which will continue to take place, as and when they happen. It aims to ensure local tactical issues are settled locally between local commanders on the ground,” said an official.Guests from the Chinese People's Liberation Army attend a reception to celebrate the 87th anniversary of the founding of the PLA in Hong Kong.Since then, the two countries have discussed implementation of “different practical measures”, which range from hotlines between formation commanders to additional border personnel meeting (BPM) points to “small platoon-level tactical exercises”, as also regular military exchanges at different levels.This includes meetings between the commanders-in-chief of Indian Army’s Eastern Command (Kolkata) and Chinese Chengdu Military Region (CMR) as well as Northern Command (Udhampur) and Lanzhou Military Region (LMR). “Though there is broad understanding at the higher levels, it will take some time to make the BDCA fully operational on the ground,” said the official.