The Syrian Electronic Army (SEA) announced on Twitter it was responsible for the cyber attack, which rendered the New York Times website inaccessible to some users for several hours starting at around 3 p.m. (1900 GMT) Tuesday.

"Our initial assessment is that this is most likely the result of a malicious external attack," the newspaper said in a statement on Facebook.

Twitter said that the viewing of videos and photos was "sporadically affected," while the Huffington Post news and blogging website said its UK internet presence was targeted.

The SEA claimed responsibility for all three incidents. The group has previously taken responsibility for similar attacks on other large media organizations, including the Financial Times, the BBC and the Associated Press news agency. The Washington Post newspaper blamed the SEA for hacking their website earlier this month.

Wednesday's hacking appears to have targeted the Domain Name System that serves as a directory of sorts for routing online traffic to various websites. Wednesday's attack hit an Australian domain registration service that manages domain names for Twitter and the Times, among others.

dr/jm (AFP, dpa, Reuters, AP)