China accused Indian troops of violating a bilateral agreement and firing warning shots in the air during a confrontation with Chinese personnel on the disputed border on Monday, amid renewed tensions between the two countries.

Chinese border guards took “countermeasures” to stabilise the situation, Zhang Shuili, spokesman for the military’s western command theatre, said in a statement published by the military’s official news website early on Tuesday.

The statement did not make clear what those measures were or whether Chinese troops also fired warning shots.

India, on the other hand, rejected Chinese allegations of violating border agreements and accused Chinese troops of firing in the air during a face-off on their tense de facto border.

“It is the PLA that has been blatantly violating agreements and carrying out aggressive manoeuvres, while engagement at military, diplomatic and political level is in progress,” the Indian army said in a statement.

It said Chinese soldiers tried to close in on a forward Indian position in the Ladakh sector in the western Himalayas and when they were met by Indian troops, the PLA fired a few rounds in the air.

Both sides have observed a long-held protocol to avoid using firearms on the sensitive, high altitude frontier running through the western Himalayas, though this agreement has not prevented casualties.

Twenty Indian soldiers were killed in hand-to-hand fighting in a clash in June, an incident that led to China and India deploying additional forces along the frontier.

“We request the Indian side to immediately stop dangerous actions...and strictly investigate and punish personnel who fired shots to ensure that similar incidents do not occur again,” Zhang said in the statement.

The disputed and undemarcated 3,500-kilometer (2,175-mile) border between India and China, referred to as the Line of Actual Control, stretches from the Ladakh region in the north to the Indian state of Arunachal Pradesh.

China says the frontier is about 2,000 kilometers (1240-mile) and claims entire Arunachal Pradesh as its territory.