HONG KONG — Days after the comedian John Oliver mocked China’s president, Xi Jinping, on his HBO program, the authorities in that country now appear to have blocked internet users from gaining access to the network’s online content.

The HBO website has been inaccessible to mainland Chinese internet users since Saturday, according to GreatFire.org, an internet censorship watchdog.

The latest effort to erase Mr. Oliver from the Chinese internet comes after measures the authorities implemented last week to scrub any mention of the British-born comedian on Weibo, a popular Chinese microblogging platform.

HBO, which is distributed throughout the region by the subsidiary HBO Asia, is unavailable on mainland China’s cable and satellite systems except at “foreign housing compounds” such as hotels. Mr. Oliver’s show, however, was never included in HBO Asia’s programming lineup.