China has accused Indian troops of illegally crossing a disputed border and firing “provocative” warning shots at patrolling soldiers.
Chinese guards were “forced to take countermeasures”, said a military spokesperson, though it is not clear what they were.
It would be the first time in 45 years that shots were fired there, breaking an agreement barring firearm use.
Relations between both countries have steadily deteriorated in recent months.
According to state media outlet the Global Times, the Indian troops had “illegally crossed the Line of Actual Control (LAC) into the Shenpao mountain region near the south bank of Pangong Tso Lake”, quoting senior colonel Zhang Shuili, a spokesperson of the People's Liberation Army.
India's move “seriously violated related agreements reached by both sides, stirred up tensions in the region… and is very vile in nature,” said Mr Zhang.
The Indian authorities have yet to respond.
A 1996 agreement between both countries bars the use of guns and explosives from the Line of Actual Control, as the disputed border is known, although soldiers have clashed there before.
The incident reportedly took place near the Pangong lake
