Egypt's top appeals court overturned on Wednesday sentences of death and life imprisonment for 16 defendants that had been convicted of involvement in street violence in the aftermath of the 2013 ouster of Islamist president Mohamed Morsi.
The court has ordered a retrial in the case.
Two of the defendants were sentenced to death last year and 14 were handed life imprisonment terms over charges including murder, undermining public peace, the deliberate sabotage of public buildings, illegal protesting and terrorising citizens.
The charges stem from violence near the US embassy in downtown Cairo in October 2013. One person was killed and many others were wounded during clashes with security forces at the time.
Wednesday's court decision does not include convictions against others in the same case who were sentenced in absentia, who will automatically be retried if they turn themselves in, according to Egyptian law.