BEIJING (AP) — Chinese internet users have lost access to Microsoft Corp.'s Bing search engine, setting off grumbling about the ruling Communist Party's increasingly tight online censorship.

Comments left Thursday on internet bulletin boards accused regulators of choking off access to information. Others complained they were forced to use Chinese search engines they say deliver poor results.

Bing complied with government censorship rules by excluding foreign websites that are blocked by Chinese filters from search results. But the government has steadily tightened control over online activity.

Microsoft confirmed in a statement Bing was inaccessible. It says the company is trying to "determine next steps" but gave no details.