Egypt's prosecutor-general Hisham Barakat referred on Sunday 31 suspects to the criminal court over the killing of four Shiites last year.
Shiite leading figure Hassan Shehata was killed alongside three other Shiites in June, 2013 when a crowd of people attacked a religious gathering in a Giza village.
The 31 defendants are accused of murder, attempted murder, torching, illegal assembly, vandalism and possession of unlicensed weapons, said Osama Hanafy, head of the South Giza prosecution.
A group of Salafis crowded outside the house of one Shiite last June, attacking the house with rocks and Molotov cocktails and accusing those gathered inside of blasphemy.