Pakistan has blocked access to Wikipedia for failing to remove what authorities considered "blasphemous content".
The Pakistan Telecommunication Authority had earlier in the week given the online encyclopaedia 48 hours to remove the material, without publicly specifying its exact objections.
Blasphemy is a sensitive issue in Muslim-majority Pakistan, and social media giants Facebook and YouTube have previously been banned for publishing content deemed sacrilegious.
A spokesman for the telecoms regulator, Malahat Obaid, said Wikipedia was blocked across the country on Friday "after it failed to respond to our repeated correspondence over removal of the blasphemous content and meet the deadline".
"They did remove some of the material but not all," Mr Obaid said. "It will remain blocked until they remove all the objectionable material."
Pakistan's Dawn newspaper reported that users trying to access Wikipedia on Saturday were met with the message “this site cannot be reached”.
Wikipedia is written and maintained by a community of volunteers, through open collaboration.
The Wikimedia Foundation, the non-profit fund managing the website, said the block "denies the fifth most populous nation in the world access to the largest free knowledge repository".
"If it continues, it will also deprive everyone access to Pakistan's knowledge, history, and culture," it said.
Free speech campaigners have highlighted what they say is a pattern of rising government censorship of Pakistan's printed and electronic media.
"There's just been a concerted effort to exert greater control over content on the internet," said digital rights activist Usama Khilji.
"The main purpose is to silence any dissent," he told AFP. "A lot of times blasphemy is weaponised for that purpose."
Pakistan blocked YouTube from 2012 to 2016 after it carried a film about the Prophet Mohammed that led to violent protests across the Muslim world.
In recent years, the country has also blocked the popular video-sharing app TikTok several times over "indecent" and "immoral" content.
With reporting from AFP
