The New York Times and Twitter on Tuesday became the latest American media organizations to succumb to hacking attacks, in another series of disruptions apparently caused by the shadowy group known as the Syrian Electronic Army.

The SEA, which is aligned with Syrian President Bashar al-Assad, asserted responsibility for disrupting access to the sites starting in the late afternoon and continuing into Wednesday. But neither the Times nor Twitter cited a specific source.

Little is known about the members of the SEA, but the group appears to be based in Syria, a country split by civil war and facing the threat of a military strike by the United States and its allies over the Assad government’s alleged use of chemical weapons.

The hacking group has been responsible for earlier digital attacks on Britain’s Guardian newspaper, the Associated Press and The Washington Post. It was behind an incident that briefly redirected some readers to the group’s Web site when they were attempting to reach some articles on The Post’s Web site.

Some readers could not access the New York Times site; others were redirected to a Web page featuring what appeared to be the SEA’s logo.

Twitter remained functional for many users, too, although the company said in a statement that some of its domain codes were “modified” and that “viewing of images and photos was sporadically impacted” over about a 90-minute period. It made no mention of the cause of the problem. It also said no user information was affected.

But at one point, the SEA claimed it had taken over Twitter’s domain, or Web address, which would enable it to shift traffic headed to the site to its own servers.

The outage at the Times was its second in two weeks. The newspaper said the first one, on Aug. 14, was due to an internal problem.

This time, spokeswoman Eileen Murphy said the cause was a “malicious external attack,” but she didn’t identify the source.

Sophos security researcher Chester Wisniewski confirmed that the name servers listed on a directory entry are controlled by

August has been a particularly bad month for prominent outages. Several news Web sites, including The Post, were affected by a breach at the third-party content provider Outbrain, which redirected some visitors to sites promoting the Syrian Electronic Army.

Google and Amazon were hit with technical problems that took down their Web sites. An Amazon Web Services outage this past weekend also affected the performance of services such as Netflix, Instagram and Vine. Last week, the Nasdaq Stock Market was forced to halt trading for three hours after a “technical glitch.”