ISLAMABAD, Pakistan — Pakistani authorities broadened what started as a ban on a social networking site on Thursday, blocking YouTube and about 450 individual Web pages over what they described as “growing sacrilegious content.”

The Pakistan Telecommunication Authority blocked YouTube after a special Internet monitoring unit within the agency determined that “objectionable content” was increasing, according to a spokesman, Khurram Mehran.

“Earlier we were blocking the links,” he said of YouTube, “but when content increased we had to block the whole Web site.”

The ban, which also included certain pages on the Flickr and Wikipedia sites, occurred a day after access to Facebook was suspended on orders from a Pakistani court. A group of Islamic lawyers won that injunction, arguing that a contest, started by users for drawings of the Prophet Muhammad and called “Everybody Draw Muhammad Day,” was offensive. Depiction of Muhammad is considered blasphemous by some Muslims.