Twitter, Facebook and YouTube were functioning normally in Turkey on Tuesday after Ankara lifted a ban it imposed on them over images of a Turkish prosecutor killed in a hostage standoff.

The popular social media sites were blocked for several hours on Monday after a court ordered a ban on websites that published images of the prosecutor, who was taken hostage by leftist militants at an Istanbul court last week.

He and his captors were eventually killed after police stormed the building.

Access was restored after the websites complied with the court order and took down the offending images.

During the siege, the DHKP-C group that claimed responsibility published pictures showing one of the militants -- his face concealed by a scarf with the group's red and yellow insignia -- holding a gun to the hostage's head in the prosecutor's offices.

The images were circulated on social media while the siege was ongoing and were published by several Turkish newspapers as well as news websites.

Publication of any material related to the hostage standoff amounted to "terrorist propaganda" inciting people to "hatred and violence" and disturbing the public order, the court ruling read.