The Chinese military was "forced to take countermeasures" to maintain stability at the China-India border after Indian troops trespassed via the southern bank of Pangong Tso Lake on Monday and fired warning shots at Chinese border patrols, said Senior Colonel Zhang Shuili, spokesman for the People's Liberation Army Western Theater Command, in a statement on early Tuesday.

It is the second time Indian troops violated the Chinese border in eastern Ladakh of China's Tibet autonomous region in the last two weeks. In the second incident, the PLA personnel were about to negotiate with the Indian side when they were fired upon by Indian soldiers, Zhang said.

A source in New Delhi confirmed the incident without giving any details. It is unclear if there are any casualties. The incident came three days after defense ministers from both countries met in Moscow and agreed to de-escalate the border situation.

Zhang called the shots a serious violation of relevant agreements between the two countries and a "serious military provocation" that has escalated tension further and could easily lead to misunderstandings. As a result, the Chinese border troops "were forced to take necessary countermeasures to get the situation under control," he said.

Zhang urged the Indian side to immediately stop its dangerous actions, pull back troops that have entered Chinese territory, strictly restrain the behavior of its front-line servicemen, and seriously investigate and punish the person who fired on the Chinese soldiers to ensure similar incidents do not occur again.

The PLA Western Theater Command will uphold its duties and missions to staunchly safeguard national sovereignty, he added.