In the fourth such incursion since March, two helicopters of the People's Liberation Army of China hovered for about five minutes in Uttarakhand's Chamoli district and "could have carried out aerial photography of Indian ground troops," according to official sources in the government.
China on Monday defended PLA helicopters hovering over the Barahoti region of Uttarakhand's Chamoli district, saying India and China have a territorial dispute in
the eastern section of their boundary and the Chinese military carry out regular patrolling in the relevant areas.
While the details can be obtained from the ministry of defence, "in principle China and India have territorial disputes in the eastern section of the China-India border", Chinese foreign ministry spokesperson Hua Chunying told the media when asked about reports that PLA helicopters violated Indian airspace on Saturday.
"The Chinese military carry out regular patrolling in the relevant areas. We hope that the two sides will make joint efforts to maintain tranquillity and peace in the border areas," Hua said.
Two helicopters of the People's Liberation Army of China hovered over Chamoli district on Saturday, triggering concern in India's security establishment about the PLA's fourth such incursion into Indian airspace since March this year.
Official sources in New Delhi said the choppers, which returned to the Chinese side after about five minutes, could have carried out aerial photography of Indian ground troops during what was possibly a reconnaissance mission.
The choppers were identified as the Zhiba series of attack helicopters.
The Indian Air Force (IAF) is probing the incident.
On previous occasions, Chinese helicopters had entered 4.5 kilometres into Indian territory, an area that China claims as its own and recognises as Wu-Je.
Barahoti is one of three border posts in the sector, comprising Uttar Pradesh, Himachal Pradesh and Uttarakhand, where ITBP jawans are not allowed to carry weapons and are in civilian clothes under a unilateral decision taken by the central government in June 2000.
In 1958, India and China listed Barahoti, an 80 sq km sloping pasture, as a disputed area where neither side would send their troops.
In the 1962 India-China war, the PLA did not enter the 545-km middle sector, focusing on the Western (Ladakh) and Eastern (Arunachal Pradesh) sectors.
However, after the 1962 war, ITBP jawans patrolled the area with weapons in a non-combative manner, under which the barrel of the gun is positioned downward.
During prolonged negotiations on resolving border disputes, the Indian side had unilaterally decided in June 2000 that ITBP troops would not be carrying arms to three posts -- Barahoti, Kauril and Shipki in Himachal Pradesh.
The India-China border dispute covers the 3,488 km long Line of Actual Control (LOAC). While China claims Arunachal Pradesh in the Eastern Section as Southern Tibet, India asserts that the dispute covered Aksai Chin area which was occupied by China during 1962 war.
Image of Chinese helicopters used for representational purposes only. Photograph: Kind Courtesy eng.chinamil.com.cn, a website sponsored by the Chinese People's Liberation Army.