An unidentified Chinese warship demanded that an Indian naval vessel identify itself and explain its presence in South China Sea waters off Vietnam in July.
The London-based newspaper reported that five people familiar with the incident said it occurred in international waters shortly after India’s amphibious assault ship INS Airavat completed a scheduled port call in Vietnam.
It is the latest in a series of actions this year that have caused concern about Beijing’s maritime assertiveness among regional nations — particularly Vietnam and the Philippines.
China says it has sovereignty over essentially all of the South China Sea, a key global trading route, where its professed ownership of the potentially oil-rich Spratly archipelago overlaps with claims by Vietnam, the Philippines, Taiwan, Brunei and Malaysia.
Vietnam and China have a separate long-standing dispute over the more northerly Paracels archipelago.
The INS Airavat visited Nha Trang in south-central Vietnam and the northern port of Haiphong in the second half of July.
In recent months, the Philippines and Vietnam have objected to what they said was Chinese harassment of oil exploration vessels and fishermen in the South China Sea.
US Secretary of State Hillary Clinton in July condemned acts of “intimidation” in the waters, where it says it has a national interest in free navigation.