India said on Monday it expects China to provide assurances that Indian nationals transiting through Chinese airports will not be "selectively targeted, arbitrarily detained, or harassed," after an Indian citizen was detained at Shanghai airport last month.

New Delhi had lodged a strong protest with Beijing over what it called the arbitrary detention of an Indian citizen at the airport, saying such incidents undermine efforts to rebuild ties.

Indian media reported that Prema Wangjom Thongdok, a UK-based woman with an Indian passport, was stopped during a layover on 21 November and told her passport was invalid because she was born in the eastern state of Arunachal Pradesh.

She was prevented from boarding her onward flight to Japan and held for 18 hours.

Beijing says Arunachal Pradesh, which it calls Zangnan, is a part of southern Tibet, a claim India rejects.

"We expect the Chinese authorities to provide assurances that Indian citizens transiting through Chinese airports will not be selectively targeted, arbitrarily detained, or harassed, and that regulations governing international air travel would be respected," Indian foreign ministry spokesperson Randhir Jaiswal told reporters at a weekly media briefing.

He also advised Indian nationals to "exercise due discretion" when traveling to or through China.

The Chinese foreign ministry did not immediately respond to a request for comment on Monday. Last month, Beijing said airport checks were conducted in accordance with laws and regulations.

Cautious rapprochement

India and China have been cautiously improving ties after years of tension, marked by high-level visits including Prime Minister Narendra Modi's trip to China in August – the first in seven years – where he and President Xi Jinping pledged partnership over rivalry.

Relations soured after a 2020 Himalayan clash that killed 20 Indian and four Chinese soldiers in hand-to-hand combat. The two countries share a 3,800 km (2,400-mile) disputed border.