Messages by the international hacking group Anonymous went up on a number of Chinese government websites on Thursday to protest internet restrictions.

On a Twitter account established in late March, Anonymous China listed the websites it said it had hacked over the last several days. They included government bureaus in several Chinese cities, including in Chengdu, a provincial capital in southwest China.

Some of the sites were still blocked on Thursday, with English-language messages shown on how to circumvent government restrictions. In a message left on one of the hacked Chinese sites, cdcbd.gov.cn, a home page for Chengdu's business district, the hackers expressed anger with the Chinese government for restrictions placed on the internet.

"Dear Chinese government, you are not infallible, today websites are hacked, tomorrow it will be your vile regime that will fall," the message read. "So expect us because we do not forgive, never. What you are doing today to your Great People, tomorrow will be inflicted to you," one of the messages read.

Al Jazeera's Melissa Chan, reporting from Hong Kong, said that the attack was interesting because Anonymous had mostly previously stayed away from attacking Chinese websites.

"This is just (Anonymous') second attack (on Chinese websites)," Chan said. "The first one a few months ago had been a corporate attack against a Chinese company and it had exposed corporate fraud. This time, of course, the message was more general about online censorship in China."

Chan also pointed out the attacks did not target national websites, but smaller sites for government bureaus and minor cities.

"The other interesting thing is that the messages they left were left in English, so then that begs the question of whether they wanted to try to reach out to the Chinese public or not," Chan said.

Some websites that Anonymous said it attacked were working Thursday, and government officials denied the sites were ever hacked.