Update, Friday, 8:15 a.m.: Anonymous says it will hack more Chinese sites. “It will keep going. The targets are selected,” the group told the AFP in an e-mail. Read more here.

At least one Chinese government Web site has not recovered after being hacked by Anonymous yesterday:

The hacked home page for Chengdu city’s business district.

An Anonymous China Twitter account said more than 400 Web sites were hacked, including the sites of government bureaus in several Chinese cities, including the city of Chengdu, whose Web site is pictured above.

On Thursday, a message on that site from the hacking group told Chinese citizens to “never, ever give up” in challenging their government about a “lack of democracy and justice.” Anonymous said the hack was in protest of Internet restrictions in the country.

The hack was significant in part because Anonymous previously stayed away from Chinese Web sites, according to al-Jazeera.

Last fall, Anonymous backed off of a threat to unmask members of the Mexican drug cartel the Zetas, reportedly because of the Zetas had planned to retaliate.

It is unclear whether the Chinese government’s army of Internet trolls will fire back on Anonymous for this attack.

Internet freedom is a major problem in China, where government censors delete thousands of messages online, social media networks require users to use their real names, and the online media is often stifled.