"We’ve confirmed that Bing is currently inaccessible in China and are engaged to determine next steps," the company said in a Wednesday statement.
It is the U.S. technology giant’s second setback in China since November 2017 when its Skype internet phone call and messaging service was pulled from Apple and Android app stores.
A search performed on Bing’s China website - cn.bing.com - from within mainland China directs the user to a page that says the server cannot be reached.
The Financial Times, citing a source, reported on Wednesday that China Unicom (0762.HK), a major state-owned telecommunication company, had confirmed the government order to block the search engine.
Cyberspace Administration of China (CAC), a government watchdog, did not respond to faxed questions about Bing’s blocked website.
Bing was the only major foreign search engine accessible from within China’s so-called Great Firewall. Microsoft censored search results on sensitive topics, in accordance with government policy.
Microsoft also has a partnership with Chinese data center provider 21Vianet to offer its products Azure and Office 365 to clients in the country.
Alphabet’s (GOOGL.O) Google search platform has been blocked in China since 2010. Google CEO Sundar Pichai said in December it has "no plans" to relaunch a search engine in China though it is continuing to study the idea amid increased scrutiny of big tech firms.
In a statement on Wednesday, CAC said it had deleted more than 7 million pieces of online information and 9,382 mobile apps. It also criticized technology company Tencent’s news app for spreading "vulgar information."