Egyptian authorities detained at least 200 activists, halted a planned activists’ march to Gaza, preventing participants from reaching the border to protest Israel’s unlawful blockade of humanitarian aid before the demonstration could begin.

To draw attention to the humanitarian crisis afflicting people in Gaza, marchers have for months planned to trek 30 miles (48 kilometers) across the Sinai Peninsula to Egypt's border with the enclave on Sunday to "create international moral and media pressure” to open the crossing at Rafah and lift a blockade that has prevented aid from entering.

Authorities have deported more than three dozen activists, mostly carrying European passports, upon their arrival at the Cairo International Airport in the past two days, an Egyptian official said Thursday. The official said the activists aimed to travel to Northern Sinai "without obtaining required authorizations.” The official spoke on condition of anonymity because he wasn’t authorized to brief the media.

Egypt has publicly denounced the restrictions on aid entering Gaza and repeatedly called for an end to the war. It has said that the Egyptian side of the Rafah crossing remains open, but access to the strip has been blocked since Israel seized the Palestinian side of the border as part of its war with Hamas that began in October 2023.

Food security experts warn the Gaza Strip will likely fall into famine if Israel doesn’t lift its blockade and stop its military campaign. Nearly half a million Palestinians are facing possible starvation, and 1 million others can barely get enough food, according to findings by the Integrated Food Security Phase Classification, a leading international authority.

Israel has rejected the findings, saying the IPC’s previous forecasts had proven unfounded.

The Egyptian government has for years clamped down on dissidents and activists when their criticism touches on Cairo’s political and economic ties with Israel, a sensitive issue in neighboring countries where governments maintain diplomatic relations with Israel despite broad public sympathy for Palestinians and the former's war crimes and systematic abuses against them.

Egypt had earlier warned that only those who received authorization would be allowed to travel the planned march route, acknowledging it had received "numerous requests and inquiries.”

"Egypt holds the right to take all necessary measures to preserve its national security, including the regulation of the entry and movement of individuals within its territory, especially in sensitive border areas,” its foreign ministry said in a statement on Wednesday.

Israel Katz, Israel’s defense minister, said the protesters "endanger the Egyptian regime and constitute a threat to all moderate Arab regimes in the region.”

The march is set to begin just days after a large convoy, which organizers said included thousands of activists, traveled overland across North Africa to Egypt.

Activists and attorneys said airport detentions and deportations began Wednesday with no explicit reason given by Egyptian authorities.

Algerian attorney Fatima Rouibi wrote on Facebook that Algerians, including three lawyers, were detained at the airport on Wednesday before being released and ultimately deported back to Algiers on Thursday. Bilal Nieh, a Tunisian activist who lives in Germany, said he was deported along with seven others from northern Africa who also hold European passports.

He wrote on Facebook early Thursday that authorities "didn’t give any reason or document stating the reason for deportation.”

Governments of countries whose citizens were reportedly detained or deported, including France, had not issued any public comment on the activists as of Thursday morning.

Organizers said in a statement that they had received reports that at least 170 participants had been delayed or detained in Cairo. They said they had followed the protocols laid out by Egyptian authorities, met with them and urged them to let march participants into the country.

"We look forward to providing any additional information the Egyptian authorities require to ensure the march continues peacefully as planned to the Rafah border," they said in a statement.

As global calls intensify for Israel to ease restrictions on humanitarian aid to Gaza, a convoy of aid vehicles dubbed Sumud — Arabic for "steadfastness" — has arrived in the Libyan capital of Tripoli, hoping to reach the besieged Palestinian enclave through Egypt.

The convoy, which departed from the Tunisian capital on Monday, is attempting to navigate a complex route through divided Libya and Egypt, with passage permits from Egyptian authorities still pending, organizers said Wednesday.

Israel has come under growing international pressure after 21 months of war in Gaza, where the United Nations has described conditions as dire, labeling the enclave "the hungriest place on Earth."

Sumud’s progress remains uncertain as it seeks entry into eastern Libya, a region under the control of forces loyal to putschist Gen. Khalifa Haftar, a rival to Libya’s internationally recognized government based in Tripoli.

The convoy is part of a broader initiative coordinated by the Global March to Gaza, which plans a solidarity event on Friday with an estimated 4,000 participants from over 40 countries. Many have already gathered in Egypt to prepare for the march.

According to organizers, participants will travel by bus to the North Sinai city of El-Arish before marching roughly 50 kilometers (30 miles) toward the Rafah border crossing with Gaza. The group intends to camp near the border before returning to Cairo on June 19.

The Global March to Gaza is the latest civil society effort pressing for the entry of food, fuel, medical supplies, and other aid into Gaza. Israel imposed a total blockade in March in an attempt to pressure Hamas to disarm and to release hostages taken in Hamas’ Oct. 7, 2023.

It slightly eased restrictions last month, allowing limited aid in, but experts warn the measures fall far short.

Israel’s genocidal attacks have killed over 52,000 Palestinians, mostly women and children.