New Delhi has asserted that Arunachal Pradesh is an “integral part” of India in response to Beijing’s claim over the territory as the two countries rowed over the detention of an Indian citizen at Shanghai Airport.

On Tuesday, India had issued a demarche to China over the detention of Prema Wangjom Thongdok, a UK-based woman from Arunachal Pradesh, at the Shanghai airport. Thongdok had said immigration officials had held for 18 hours and “mocked” her by saying the region was not a part of India.

China says Arunachal Pradesh, which Beijing calls Zangnan, is a part of South Tibet — a claim India has repeatedly dismissed. Beijing has renamed places in the northeastern Himalayan state multiple times, prompting strong reactions from New Delhi.

Responding to queries during a press briefing on Tuesday, China’s foreign ministry spokesperson Mao Ning had said that “Zangnan is China’s territory”.

“The Chinese side has never recognised the so-called ‘Arunachal Pradesh’ illegally set up by India,” she said. She further stated there was “no so-called ‘detaining’ or ‘harassing’” of the woman at the Shanghai Pudong International Airport, adding that authorities carried out checks in accordance with the law.

Subsequently, in a statement issued on Tuesday night, Indian foreign ministry spokesperson Randhir Jaiswal said New Delhi had seen China’s remarks about Thongdok’s “arbitrary detention”.

“Arunachal Pradesh is an integral and inalienable part of India, and this is a self-evident fact. No amount of denial by the Chinese side is going to change this indisputable reality,” Jaiswal said.

On the woman’s detention, he said the issue had been taken up strongly with the Chinese authorities, who he said “have still not been able to explain their actions, which are in violation of several conventions governing international air travel”.

“The actions by the Chinese authorities also violate their own regulations that allow visa-free transit up to 24 hours for nationals of all countries,” the spokesperson noted.

Arunachal Pradesh woman’s ‘detention’ amidst attempts to improve ties

The recent row between the two countries, who have been cautiously strengthening ties after four years of hostility, erupted after Thongdok claimed she was held back at the Shanghai airport for 18 hours on November 21.

Thongdok said she was an Indian citizen who had been residing in the United Kingdom for about 14 years, and was detained by immigration staff at the Shanghai airport, where she had a layover during her trip from London to Japan.

“They called my Indian passport invalid as my birthplace is Arunachal Pradesh, which they claimed is Chinese territory,” she had said on social media platform X on November 23, referring to Chinese immigration officials and China Eastern Airlines’ staff.

She had reached out to the Indian embassies in Shanghai and Beijing, resulting in officials intervening to help her leave the country.

Thongdok said the immigration officials declared her visa unacceptable and “mocked” her, saying Arunachal Pradesh was not a part of India. “You’re Chinese, you’re not Indian,” the woman quoted them as saying.

Indian Prime Minister Narendra Modi visited China in August for the first time in seven years, where he and Chinese President Xi Jinping pledged that the two countries were partners, not rivals.

India and China share a 3,800-kilometre border that is poorly demarcated and has been disputed since the 1950s.

Ties were ruptured after a 2020 clash in the Himalayas, in which 20 Indian and four Chinese soldiers died in hand-to-hand combat.