A Cairo criminal court handed sentences on Wednesday ranging from three to seven years in prison to 18 "Muslim Brotherhood members" on charges of inciting riots.
Arrested last July during a demonstration in Cairo's Shubra district supporting ousted president Mohamed Morsi, the defendants are also accused of illegal assembly, thuggery and the possession of unlicensed arms.
Since the Islamist leader's removal on 3 July, a year after his inauguration, his supporters have continuously staged demonstrations to demand his reinstatement.
Interim authorities launched a campaign of arrests against Brotherhood leaders, members and sympathisers when a wave attacks, mostly targeting police stations, erupted after security forces forcibly dispersed two large pro-Morsi protest camps in August.
The security crackdown eventually resulted in a drastic decline in the number of demonstrations organised by loyalists of the deposed president.
Those behind bars include Morsi himself and Brotherhood supreme guide Mohamed Badie.
In December, the Islamist group was declared a terrorist organisation after the government held it responsible for orchestrating a growing number of militant attacks against the police and army.
Asserting his group's condemnation of violence, Brotherhood secretary-general Mahmoud Hussein issued on Tuesday a lengthy statement stressing that, throughout its history, the group has strictly adhered to peaceful means of struggle, distancing itself from anyone who chose to behave differently.