Mada Masr, an independent Egyptian media outlet that has published investigative reports on corruption, was also inaccessible last night.
Egypt has accused Jazeera of supporting the outlawed Muslim Brotherhood movement it blames for violence after the military ousted them from power in 2013.
The website for Al-Sharq, a pro-Brotherhood channel based in Turkey, was also blocked.
The security official said 21 websites had been blocked but one of those he listed was still accessible.