CAIRO (AP) — A crackdown by Egyptian authorities on the most prominent human rights group still operating in the country sparked a storm of condemnations of Egypt's rights record Friday by the U.N. and global advocacy groups, as well as Western diplomats and politicians.

This week, security forces arrested three senior staff members of the Egyptian Initiative for Personal Rights, including its executive director. The State Security Prosecutors leveled terror-related charges against them and ordered their pre-trail detention for 15 days.

During a press briefing in Geneva, the U.N. Human Rights Office Spokeswoman Ravina Shamdasani denounced the arrests as “a very worrying development that underscores the extreme vulnerability of civil society activists in the country.”

She expressed worry the arrests were "part of a broader pattern of intimidating organizations defending human rights and of the use of counter-terrorism and national security legislation to silence dissent.”

On Thursday, security forces arrested Gasser Abdel Razek, a veteran human rights advocate and the EIPR executive director, from his home in Cairo. A day earlier, Karim Ennarah, the head of the group's criminal justice unit was arrested while on vacation in the Red Sea resort of Dahab in South Sinai. Ennarah’s arrest came three days after security forces in Cairo detained Mohamed Basheer, EIPR's administrative director.

The arrests came after ambassadors and senior diplomats from 13 Western countries met with EIPR earlier this month for talks that EIPR said “discussed ways to improve human rights conditions in Egypt.”

The government of President Abdel-Fattah el-Sissi has been waging the heaviest crackdown on dissent in Egypt's modern history, targeting not only Islamist political opponents but also security pro-democracy activists, journalists and online critics.

Independent local rights groups have largely stopped operating. The 18-year-old EIPR is the most prominent of the few still active, continuing to work on documenting civil rights violations, prison conditions, sectarian violence and discrimination against women and religious minorities. An Egyptian who previously researched gender rights for the group, Patrick George Zaki, has been in detention since February after being arrested on return from Italy, where he was a student.

Amnesty International urged Egyptian authorities to end “the vicious reprisal campaign” against EIPR, calling upon countries whose representatives visited the group to press for the activists' release.

"The tepid response by the international community risks emboldening the Egyptian authorities and sends a terrifying message to civil society that human rights work will not be tolerated,” Philip Luther, Amnesty International’s Middle East and North Africa Research and Advocacy Director said in a statement.

So far, few of the countries who attended the gathering have spoken out publicly. In the past, some have tried behind-the-scenes with Egyptian officials to free prominent activists or journalists, with mixed success.

On Friday, the German human rights commissioner, Norway's state secretary for foreign affairs and Denmark's ambassador to Egypt — whose countries attended the meeting — issued statements condemning or expressing concern over the arrests.

“These arrests are evidently directly related to a visit by a group of ambassadors, including the German. I very clearly condemn this escalation in action against Egyptian civil society,” Germany's Bärbel Kofler said. She called for the activists' release.

Earlier, France, whose ambassador also was at the EIPR visit, expressed “deep concern” over the first arrest. In response, the Egyptian government said it would not tolerate any interference in its internal affairs.

Other nations also weighed in. Ireland's ambassador to Egypt, Sean O Regan, defended the group’s right to meet with diplomats. “Meeting with a wide range of interlocutors, including members of civil society, is an integral part of normal diplomatic practice in every country,” he wrote in a tweet.

The clampdown on the widely-respected rights group also caught the attention of some US members of Congress. On Thursday, former presidential hopeful Sen. Elizabeth Warren tweeted that the group’s members should be immediately released and allowed to defend rights without any interference.

The Chairman of the House Subcommittee on Middle East, North Africa & International Terrorism. Democratic Rep. Ted Deutch wrote a tweet condemning “the persecution” of rights defenders in Egypt. He dismissed the arrests as another episode of “a growing trend of disturbing, politically motivated actions” by Egyptian authorities.