Authorities in China have shut down Marriott's local website for a week after the USA hotel giant mistakenly listed Chinese-claimed regions such as Tibet and Hong Kong as separate countries.

Earlier on Friday China's aviation authority said it had asked Delta Air Lines to investigate why Taiwan and Tibet were listed as countries on its website, and demanded an "immediate and public" apology.

Chinese news websites carried screenshots of what they said were the websites of other prominent foreign brands that included Taiwan on lists of countries before being abruptly changed this week.

Separately, the same regulator that penalized Marriott - the Shanghai branch of the state cyberspace administration - accused Zara of placing Taiwan in a pull-down list of countries on its Chinese website.

"We are deeply sorry for the questionnaire", said Marriott Rewards, which is responsible for managing Marriott International's membership correspondence, in a statement on its official Weibo account later the same day.

City officials said in a notice dated late Wednesday that they were probing whether the gaffe in MarriottInternational's Mandarin-language questionnaire violated national cyber-security and advertising laws.

We will absolutely not support any separatist organization that will undermine China's sovereignty and territorial integrity. It asked to respondents to select their country of residence, and gave Tibet, Hong Kong, Macau and Taiwan as options alongside China. Hong Kong and Macau became British and Portuguese territories, respectively, in the age of European colonialism but are now "special administrative regions" under China.

Tibet is officially an "autonomous region" but firmly under Chinese control.

Taiwan split from China in 1949 when the Chinese Communist Party took power and former leader Chiang Kai-Shek fled to the island, formerly known as Formosa, claiming self-rule.

Foreign ministry spokesman Lu Kang told a regular briefing on Friday that Hong Kong, Macau, Taiwan and Tibet were all part of China.

"Marriott International respects China's sovereignty and territorial integrity".

Sorenson added: "Upon completion of a full investigation into how both incidents happened, we will be taking the necessary disciplinary action with respect to the individuals involved, which could include termination, changing our approval and review procedures for online content, reviewing our customer feedback channels, and enhancing training to ensure these situations don't happen again".

In a statement, Sorenson continued: "As a company, we take very seriously the privilege and opportunity we have to serve guests in countries around the world - and particularly in China, a market we have been in for over 30 years". An executive who answered the phone at Zara's Shanghai office was not able to immediately comment.