Egypt is facing a barrage of criticism over what rights groups say is a crackdown on protests and activists, as it prepares to host the COP27 climate summit starting Sunday.

Rights groups have accused the Egyptian government of arbitrarily detaining activists after Egyptian dissidents abroad called for protests to be held against President Abdel Fattah el-Sisi on November 11, during the United Nations climate talks.

According to rights groups, security forces have been setting up checkpoints on Cairo streets, stopping people and searching their phones to find any content related to the planned protests.

The Egyptian Commission for Rights and Freedoms (ECRF), an NGO, said Wednesday that 93 people had been arrested in Egypt in recent days. It said that according to national security prosecution investigations, some of those arrested have allegedly sent videos calling for protests over social messaging apps. Some were also charged with abuse of social media, spreading false news and joining terrorist organizations -- a repressive charge commonly used by the security apparatus against activists.

Indian climate activist Ajit Rajagopal was detained in Cairo last Sunday after setting off on a protest walk from the Egyptian capital to Sharm el-Sheikh, the Red Sea resort where the COP27 conference will be held from November 6 to 18. Rajagopal was released after a brief detention in Cairo along with his friend, lawyer Makarios Lahzy, a Facebook post by Lahzy said. Reuters, which spoke to Rajagopal following his release Monday, cited the Indian activist as saying he was still trying to get accredited for COP27 but did not plan to resume his march.

CNN has reached out to the Egyptian authorities for comment.

Egypt went through two mass uprisings in 2011 and 2013 which eventually paved the way for then-military chief to take power. Thousands of activists have since been jailed, spaces for public expression have been quashed and press freedom diminished.

While protests are rare -- and mostly illegal -- in Egypt, a and a brutal security regime have spurred renewed calls for demonstrations by dissidents seeking to exploit a rare window of opportunity presented by the climate summit.

One jailed activist, British-Egyptian citizen Alaa Abdelfattah, escalated his hunger strike in an Egyptian prison this week, amid warnings by relatives over his deteriorating health. "Alaa has been on hunger strike for 200 days, he's been surviving on only 100 calories of liquid a day," said Sanaa Seif, Abdelfattah's sister, who is staging a sit-in outside the UK Foreign Office in London.

A PLACE FOR DIALOGUE

COP, the annual UN-sponsored climate summit that brings together the signatories of the Paris Agreement on combating climate change, is traditionally a place where representatives of civil society have an opportunity to mingle with experts and policy makers and observe negotiations firsthand.

It is not uncommon to see a young activist approaching a national delegation walking down the corridor to their next meeting or an indigenous leader chatting to a minister on the sidelines of a debate.

And while security is always strict -- this is, after all, a gathering attended by dozens of heads of states and governments -- peaceful protests have always been part of COP. Tens of thousands of people marched through the streets of last year's host city of Glasgow, Scotland, during the summit.

Yet Egypt has tightened the rules on who can access the talks.

As in the past, this year's COP conference will take place across two different sites. The official part of the summit is run by the UN and is only accessible to accredited people, including the official delegations, representatives of NGOs and other civil society groups, experts, journalists and other observers.

Then there is a separate public venue where climate exhibitions and events take place throughout the two weeks of the summit. But while this public part of the summit was in the past open to anyone, people wishing to attend this year will need to .

The chance to protest will also be restricted.

While the Egyptian government has pledged to allow demonstrations, it has said protests will have to take place in a special "protest zone," a dedicated space away from the main conference site, and will have to be announced in advance. Guidelines published on the official COP website say that any other marches would need to be specially approved.

Anyone wanting to organize a protest will need to be registered for the public part of the conference -- a requirement that may scare off activists fearing surveillance. Among the rules imposed by the Egyptian authorities on the protests is a ban on the use of "impersonated objects, such as satirical drawings of Heads of States, negotiators, individuals."

RIGHTS GROUPS SOUND ALARM

The UN has urged Egypt to ensure the public has a say at the conference.

The UN High Commissioner for Human Rights Volker Türk said it was "essential that everyone -- including civil society representatives -- is able to participate meaningfully at the COP27 in Sharm el-Sheikh" and that decisions about climate change need to be "transparent, inclusive and accountable."

Separately, a group of five independent human rights experts, all of them UN special rapporteurs, published a statement last month expressing alarm over restrictions ahead of the summit. They said the Egyptian government had placed strict limits on who can participate in the talks and how, and said that "a wave of government restrictions on participation raised fears of reprisals against activists."

"This new wave follows years of persistent and sustained crackdowns on civil society and human rights defenders using security as a pretext to undermine the legitimate rights of civil society to participate in public affairs in Egypt," the group said in a statement.

A group of Egyptian civil rights groups has launched a petition calling for the Egyptian authorities to end the prosecutions of civil society activists and organizations and end restrictions on the rights to freedom of expression, association and peaceful assembly.

"The Egyptian authorities have for years employed draconian laws, including laws on counter terrorism, cyber crimes, and civil society, to stifle all forms of peaceful dissent and shut down civic space," the groups said in the petition.

Human Rights Watch, Amnesty International, Friends of the Earth and scores of other groups have also spoken up, demanding the release of detained activists.

In the lead-up to the climate conference, the Egyptian government presented an initiative pardoning prisoners jailed for their political activity. Authorities also pointed to a new prison, Badr-3, 70 kilometers (43 miles) northeast of Cairo, where other prisoners were moved to purportedly better conditions.

But rights groups said the government's initiatives amounted to little change.

"Ahead of COP27, Egypt's PR machine is operating on all cylinders to conceal the awful reality in the country's jails, where prisoners held for political reasons are languishing in horrific conditions violating the absolute prohibition of torture and other ill-treatment," said Agnès Callamard, Amnesty International's secretary general.

"Prisoners are facing the same human rights violations that have repeatedly blighted older institutions, exposing the lack of a political will from the Egyptian authorities to bring an end to the human rights crisis in the country."