An Indian drone has "invaded" China's airspace and crashed, the defence ministry in Beijing said on Thursday, months after the neighbours ended one of their worst border standoffs in decades.
"The Indian move violated China's territorial sovereignty. We strongly express our dissatisfaction and opposition," deputy director of the army's western theatre combat bureau, Zhang Shuili, said in a statement.
Zhang did not give details about when or where the incident happened.
Chinese border troops "took a professional and responsible attitude" and carried out identification verification of the device, Zhang said.
"We will earnestly fulfil our mission of duty and firmly defend the sovereignty and security of our country," he added.
The Indian embassy in Beijing declined to comment.
In August, the two nations pulled back their troops to resolve a tense deadlock over part of a Himalayan plateau claimed by both China and Bhutan, an ally of India.
The standoff began in mid-June after Chinese troops started building a road on the remote Doklam plateau.
India has an army base nearby and moved soldiers into the flashpoint zone to halt the work, prompting Beijing to accuse it of trespassing on Chinese soil.
After both sides withdrew, India's army chief said in September that his country could not afford to be complacent and must be prepared for war. (AFP)