CAIRO, Egypt -- An Egyptian court on Sunday convicted 23 activists, including prominent rights campaigners, of staging an illegal demonstration and sentenced them each to three years in jail.

The Cairo court also fined the defendants, who include eight women, 10,000 pounds (about $1,400) each.

The case is rooted in a peaceful demonstration the defendants had allegedly participated in last summer near the presidential palace in Cairo's Heliopolis suburb. The demonstration was called to protest a law adopted late last year severely restricting the right to stage street protests.

The defendants have also faced other charges, like damaging public property and assaulting policemen.

The conviction of the 23 is the latest in a government crackdown against liberal pro-democracy activists, many of whom were iconic figures of the popular uprising that forced longtime ruler Hosni Mubarak to step down in February 2011. The crackdown has also killed hundreds of Islamists and jailed thousands.

Among the 23 is Sanaa Seif, who hails from a family of longtime rights campaigners, including her late father Ahmed Seif al-Islam and brother Alaa Abdel-Fattah, who has recently been freed from prison pending his appeal of a 15-year jail sentence for breaking the protests law and assaulting an on-duty police officer.

Another defendant is Yara Sallam, a prominent rights lawyer.

Sunday's verdict, which can be appealed, comes at a time when Egypt is swept by nationalist sentiments following a dramatic surge in attacks blamed on Islamic militants on troops and security forces in the Sinai Peninsula while witnessing a smear campaign targeting many of the secular pro-democracy campaigners behind the 2011 uprising.

Suspected militants killed at least 30 army soldiers in the restive north of Sinai on Friday, the deadliest attack on the Egyptian army in decades. In newspaper articles and television talk shows, media celebrities loyal to President Abdel-Fattah el-Sissi have over the weekend urged the general-turned-politician to step up military actions against the militants and clamp down on dissent. El-Sissi himself on Saturday described the battle against the militants as "existential" imposed a night-to-dawn curfew in the northern part of Sinai and declared a national three-day state of mourning.

"Don't let Sinai be your final goal Mr. President. If necessary, declare Egypt from Aswan (the nation's southernmost city) to Matrouh (northernmost city) a military base, let the hand that writes a word against you be chopped off and the tongue that dares ask you 'What are you doing?' be cut off too," wrote columnist Mahmoud al-Kardousy in Sunday's edition of the daily al-Watan.

El-Sissi took office in June following his landslide victory in presidential elections held the previous month. In July last year, el-Sissi, then the nation's military chief, led the overthrow of Mohammed Morsi, an Islamist and the country's first freely elected president, after millions took to the streets to call for his removal.

Critics of el-Sissi's government maintain that placing draconian conditions on street demonstrations has robbed Egyptians of a major avenue of expression, leaving them with the social media as virtually the only medium in which to air their views.

The Interior Ministry, which controls the police, recently announced would expand monitoring of all social media networks to protect the nation's interests.