HANOI • A photo of Chinese tourists wearing T-shirts depicting Beijing's claims to the disputed South China Sea has sparked online anger in Vietnam, prompting calls for the visitors to be deported.
The shirts feature a map of China and its so-called nine-dash line - the sea boundary found on some 1940s-era maps which Beijing says proves its claim to most of the waterway, despite claims from Vietnam and other nations.
The territorial dispute is a hot-button issue in Vietnam, which has a turbulent history of conflict with its powerhouse neighbour.
The visitors arrived in the southern Cam Ranh airport on Sunday night and were stopped by security at the immigration desk, an airport police officer confirmed to Agence France-Presse.
"We asked them to take the T-shirts off before allowing them to leave the airport," said the officer, without providing his name.
Photos of the tourists in their nationalist attire made the rounds on social media - with the nine-dash line crossed out with an "X".
Some netizens said the tourists were not welcome in Vietnam.
"Immediately deport them and ban them permanently from coming to Vietnam," Facebook user Nguyen Ngoc Hieu posted.
Vietnam and China have long sparred over the resource-rich sea, where Beijing has built artificial islands and installed airstrips and military equipment.
This is not the first time the dispute has trickled into the tourism sector. A Chinese passport featuring a map of Beijing's sea claims was defaced in 2016 by a border agent in Ho Chi Minh City's airport.
Border officials in tourist hot spots Danang and Phu Quoc have also reportedly refused to issue visa stamps in Chinese passports with maps of the nine-dash line.
More than four million Chinese visitors set foot in Vietnam last year - over 30 per cent of all foreign guests - and Chinese tourists are a major cash cow.
Meanwhile another T-shirt has caused offence, this time in China.
American clothing retailer Gap has apologised to China over a T-shirt with a map showing the mainland but omitting Taiwan, becoming the latest foreign firm to run afoul of Beijing's policy on the self-ruled island.
China, which considers Taiwan a rebel province awaiting reunification, has taken airlines, hotels and other companies to task in recent months for listing the island as a separate country on their websites.
The Gap shirt, which was sold in overseas markets, features a map of China, but Taiwan does not appear to the south-east of the mainland, according to a photo posted on the Twitter account of the People's Daily.
The state-run Global Times newspaper said the map also omitted South Tibet and the South China Sea, and that the issue sparked a social media frenzy in China after a photo was posted of the T-shirt at an outlet store in Canada.
Hundreds of people complained on Gap's official account on China's Weibo microblogging website, the daily said.
The United States company issued its apology on Weibo on Monday, saying it was "terribly sorry" and that it "respects the integrity of China's sovereignty and territory".
Chinese foreign ministry spokesman Lu Kang said at a press briefing yesterday that Beijing had noticed Gap's statement, but would not say whether the government had complained to the retailer.
US hotel chain Marriott, Spanish clothing giant Zara and a slew of airlines have faced China's wrath for not classifying Taiwan as part of China on their websites.
The White House hit back at the push earlier this month, calling the demands placed on airlines "Orwellian nonsense".