Pakistan banned access to Twitter on Sunday because of “blasphemous” material, a Pakistani official said, but normal service was resumed after 12 hours.
The government did not specify which users or messages had prompted the ban on the microblogging site or why it was allowed to operate again so quickly.
Any representation of the Prophet Mohammad is deemed un-Islamic and blasphemous by many Muslims, who make up the overwhelming majority in Pakistan.
Pakistan blocked access to Facebook in May 2010 for nearly two weeks because of users conducting a competition on drawing Mohammad. Twitter, YouTube and about 1,000 other websites were also blocked for carrying blasphemous content.