The intrusion of an Indian unmanned aerial vehicle (UAV) into Chinese airspace on Thursday has triggered a tough response from China's military with experts saying China's tolerance toward India's hostility is wearing thin.

A Chinese military officer said Thursday that China strongly opposes the intrusion of the Indian drone into Chinese airspace. The Indian UAV entered Chinese airspace and crashed. Chinese border troops are investigating, said Zhang Shuili, deputy head of the combat bureau of the Western Theater Command's joint staff department, the Xinhua News Agency reported.

"India has infringed on China's territorial sovereignty, and we are strongly dissatisfied with and opposed to this. We will resolutely fulfill our mission and responsibility and defend China's national sovereignty and security," Zhang said.

China's foreign ministry spokesperson Geng Shuang said at Thursday's daily briefing that the Indian UAV entered Chinese territory and crashed in the border area close to India's Sikkim State, which is where the military standoff took place from June to August.

China has made representations with the Indian government, Geng noted.

This is not the first time that India has sent a military drone to spy on China. In the past the Chinese government and military dealt with the issue more discretely, not wanting to humiliate India in the international arena "because we care about India's feelings,' said Lin Minwang, a professor at Fudan University's Center for South Asian Studies.

"This time, our military could no longer hide the secret for India, so we can see China's attitude toward India is changing and India had better take notice," Lin said.

"We don't know how the UAV crashed but there is no denying that India's UAV crashed in Chinese territory. This is strong evidence of India's hostility," said Song Zhongping, a military expert and TV commentator.

China resolved theDoklam standoffwith sincerity and responsible in the name of regional peace, but it appears India has little appreciation of China's efforts and continues to offend, said Hu Zhiyong, a research fellow at the Institute of International Relations of the Shanghai Academy of Social Sciences. "It is dangerous to challenge China so frequently," he said.

India's explanation

The Indian defense ministry later responded to the incident on its official website, saying that an Indian UAV which was on a regular training mission inside Indian territory when it "lost contact with ground control due to some technical problem and crossed over the LAC [Line of Actual Control] in the Sikkim Sector."

"As per standard protocol," said the Indian ministry, "the Indian border security personnel immediately alerted their Chinese counterparts" and the cause of the incident "is under investigation."

"Of course India will say such a thing," Song said. "We need to wait for the results of the investigation and information released by the Chinese military, but a UAV is normally used for spying and reconnaissance missions," Song said.

"Using UAVs to spy on China is a cowardly move, and the Chinese military should not allow it to happen again," Hu said.

"We have multiple ways to bring down an UAV, including shooting it down or using electronic interference to misguide it. The PLA is capable of defending our sovereignty," Song said.