BEIJING ( TheStreet) -- Chinese search engine Baidu ( BIDU) and the popular messaging tool QQ run by Tencent Holdings were among the online services rendered inaccessible during periodic Internet Web site disruptions that swept China on Tuesday.
The official China News Service, quoting "several domain name system (DNS) service providers" operating on the mainland, said during the worst period some two-thirds of the nation's DNS servers were affected for up to an hour starting at around 3 p.m. Beijing time.
Tencent's QQ email and enormously popular QQ messaging service were inaccessible at times during the morning. Web site outages were continuing late Tuesday night.
It was unclear how many of China's 2.68 million Web sites could not be accessed during the disruptions. But Web sites with addresses using the .com domain including Baidu were apparently hardest hit.
Strictly Chinese Web sites that use addresses with the .com.cn domain were not affected, the state-run Securities Times reported.
The Chinese government's China Internet Network Information Center, or CINIC, did not comment Tuesday on the snafu. But China News Service quoted an unnamed "technical expert" as saying the "problem was likely with domestic network operators" because only Internet services on the mainland were affected.
Last summer, CINIC reported China was hit by a major, two-hour cyber attack Aug. 25 that crashed mainland servers hosting the .com.cn domain.
Despite strict government controls including routine Web site blocking, China leads the world in Internet users. Growing numbers of Chinese shop, bank and do all their business online. CINIC said the country was home to 564 million Internet users and 420 mobile Internet users as of December 31.
-- By Eric Johnson in Beijing.