The UN human rights office, the United States, and several European countries on Friday criticised the arrest of three members of a prominent Egyptian rights group after a meeting with diplomats in Cairo.
In the past week, security forces detained three staff, including the director of the Egyptian Initiative for Personal Rights (EIPR), after 13 senior diplomats visited the group for a briefing on human rights on November 3.
EIPR said all three have been ordered detained for 15 days on charges of joining a terrorist group and spreading false news, in what critics see as the latest escalation of an unprecedented clampdown on civil society and political dissent.
Egypt's government has said EIPR was operating illegally.
"We are very concerned that the targeting of human rights defenders and other activists, as well as further restrictions on freedom of expression, association and peaceful assembly imposed in the country, are having a profound chilling effect on an already weakened Egyptian civil society," Ravina Shamdasani of the UN High Commissioner for Human Rights told a briefing in Geneva.
Several European countries whose diplomats attended the November 3 meeting criticised the arrests in statements and on Twitter.
Bärbel Kofler, human rights commissioner for Germany's foreign ministry, said she was "appalled" by the arrests.
"I condemn this escalation in the way of dealing with Egyptian civil society in the strongest terms," she said in a statement.
A US Department of State spokesman said Washington was "very concerned" by the latest detention, that of EIPR Executive Director Gasser Abdel Razek.
Antony Blinken, US President-elect Joe Biden's foreign policy adviser, tweeted: "Meeting with foreign diplomats is not a crime. Nor is peacefully advocating for human rights."
Egyptian President Abdel Fattah al-Sisi has overseen an extensive crackdown on political dissent that has steadily tightened in recent years.
Sisi has said there are no political prisoners in Egypt, that stability and security are paramount, and that the government supports human rights by providing basic needs such as jobs and housing.