BEIJING – Yahoo e-mail accounts belonging to foreign journalists appeared to have been hacked and Google’s Chinese search engine was intermittently blocked Tuesday, the latest troubles in China’s heavily censored Internet market.

The Yahoo Inc. accounts of at least three journalists and an analyst became inaccessible over the past few weeks. They were greeted with messages saying, “We’ve detected an issue with your account” and were told to contact Yahoo, they said Tuesday. Yahoo technicians told one of the four that his account had been hacked and restored his access, but it was not clear if the other instances were related.

Sensitivity about Internet security has run high since Google Inc. announced in January that it might leave China after a series of cyberattacks and complaints about censorship. Last week, Google made a partial retreat, shutting down its mainland-based search engine and redirecting queries to the freer Chinese territory of Hong Kong.

Analysts have been watching closely to see if China retaliates for Google’s high-profile departure from the mainland search engine market.

Many redirected queries appeared blocked Tuesday on the Hong Kong-based search engine. Although searches for benign terms were met with results on Chinese competitors such as Baidu.com and Soso.com, an error page would pop up when the same terms were typed into Google.com.hk.

Google initially blamed the trouble on an internal revision to some search-settings coding, but backed off on that within a few hours. The company said it realized the changes had occurred a week ago without disrupting its results in mainland China.

That discovery led Google to conclude the trouble stemmed from changes in China’s “Great Firewall” — the nickname for tools the government uses to block access to sites deemed to be subversive or pornographic.

Without doing anything on its end, Google said its search traffic from mainland China appeared to be flowing freely again early today in Beijing.

“We will continue to monitor what is going on, but for the time being this issue seems to be resolved,” Google said.