The detentions of an Egyptian labor lawyer and a journalist raised concerns among rights activists Friday that the military-backed government’s crackdown on Islamists is expanding to silence other critics of its policies.

Authorities have been carrying out a wave of arrests for weeks against Islamist backers of ousted President Mohammed Morsi, who was removed in a July 3 coup. Still, his supporters have pushed ahead with protests organized by his Muslim Brotherhood denouncing the military and demanding Morsi’s return to office.

In the latest rallies, thousands flowed from mosques Friday, chanting “down with military rule” and waving Egyptian flags.

Authorities have depicted the crackdown against Islamists as part of a “fight against terror.” At least 2,000 Brotherhood members have been arrested, most on allegations of inciting violence.

A low-intensity militant insurgency has hit the Sinai peninsula and other areas in the south, where Islamist radicals have a strong base. A failed attempt to assassinate the interior minister Thursday with a car bomb has raised fears of an escalating Islamic militant campaign of revenge over the coup.

Along with the arrests, there has also been a heavy blanket of intimidation against criticism from within the non-Islamist camp against the military’s actions.

Officials frequently urge the public to unite in the face of the terror threat. Rights lawyer Gamal Eid noted how pro-military TV stations and other media smear critics of the crackdown or other policies, including branding them as a “fifth column” for the Brotherhood. Private citizens have filed legal suits against activists, accusing them of serving foreign agendas or espionage.

The detentions of labor lawyer Haitham Mohammadain and journalist Ahmed Abu-Draa raised further alarm among activists.

Mohammadain was detained from a bus Thursday at a checkpoint in the port city of Suez. He belongs to the Revolutionary Socialists, a well-known leftist group that took part in the 2011 uprising against autocratic leader Hosni Mubarak and protests against Morsi and is now critical of the military.

His lawyer, Maha Youssef, said Mohammedain was first asked by the policeman at the checkpoint why he has a beard, which is seen as a sign of an Islamist. When he objected to the question, the policeman asked him to step out of the bus for more frisking, a power granted to police under the current emergency laws.

When the officer found papers on him identifying him as a member of the Revolutionary Socialists, the officer detained Mohammadain and wrote a police report accusing him of belonging to a secret group, Youssef said.

She said Mohammadain has yet to be formally charged or questioned.

Journalist Abu-Draa, who reports from the volatile northern Sinai, has been under arrest since Wednesday, a military official said. He faces military investigation on allegations of publishing wrong information about an ongoing security operation, taking photos of military installations without a permit and spreading rumors about the armed forces.

Abu-Draa, a resident of Sinai, questioned the military’s statements about its operations against militant groups in Sinai. During military airstrikes on a village that is a militant stronghold, Abu Draa wrote on Facebook that the strikes hit civilian areas and accused military officials of misinforming the public.

Few journalists have direct access to what is happening in Sinai because of security concerns, forcing many to rely on statement by officials. Abu Draa, an award-winning reporter who has done investigation stories in Sinai, freelances for multiple Egyptian and foreign newspapers and television channels.