Activist Ahmed Douma flashes a victory sign behind bars during his trial in Cairo. (Foad Garnosy Elmagd / Almasry Alyoum/European Pressphoto Agency)

Three Egyptian activists who helped spearhead the country’s 2011 uprising were sentenced Sunday to up to three years in prison for violating a new protest-regulation law passed by a government that itself came to power through mass demonstrations just five months ago.

The sentencing appeared to confirm fears among rights advocates that Egypt’s interim government — appointed following July’s military coup against elected president and former Muslim Brotherhood leader Mohamed Morsi — is expanding its campaign against dissidents to include non-Islamist opposition groups.

Many of the more liberal and secular pro-democracy activists, including the three sentenced Sunday, had aligned with the military to eject Morsi and the Muslim Brotherhood from power in July. But since then, their protests, too, have been suppressed by the new military-backed government.

The activists sentenced Sunday by a Cairo misdemeanor court were Ahmed Maher, Mohammed Adel and Ahmed Douma, all well-known activists who have played key roles in the pro-democracy movement for years. Each was ordered to pay a fine of $7,400 for organizing a demonstration without first notifying authorities.

They were charged in connection with a Nov. 30 protest outside a courthouse in Cairo’s central Abdeen district. Maher, accompanied by Adel and Douma, had gone to the courthouse to turn himself in on an arrest warrant that charged him with coordinating an unauthorized rally several days earlier.

A crowd of marchers turned out at the courthouse to support Maher. Police dispersed the protest and prosecutors charged Maher, Adel and Douma with unlawful assembly, attacking police officers and damaging a local cafe.

The protest law requires demonstrators to seek advance authorization from the Interior Ministry and local police stations to hold protests of 10 people or more. If authorities deny permission or do not respond, the demonstration is illegal. No demonstrations can be held overnight, near or in mosques or other religious sites, or in public squares.

In an interview in October, before his imprisonment, Maher called the law “an attempt to bring back the police state.”

Sarah Leah Whitson, director of Middle East and North African affairs for Human Rights Watch, said the arrest and prosecution of the three activists send “a strong signal” that Egypt’s government “is not in the mood for dissent at any time.”

It is “a deliberate effort to target the voices who, since January 2011, have consistently demanded justice,” Whitson said in a statement released Saturday.

Also on Saturday, a judge charged Morsi, Egypt’s first democratically elected president, with a new set of criminal violations in connection with mass protests during the 2011 revolt that toppled longtime dictator Hosni Mubarak.

Morsi, who is already facing two other trials, was charged with breaking out of prison during the 2011 revolt, murdering and abducting policemen, and “threatening the unity of the country.” The indictment included charges of damaging government buildings, a common practice during the 2011 uprising.

Sharaf al-Hourani contributed to this report.