Egyptian authorities on Friday detained or deported more foreign nationals seeking to join a pro-Palestinian march to Gaza.

Hundreds of international activists arrived in Egypt this week for the Global March to Gaza, an initiative aimed at pressuring Israel to end its blockade of the enclave.

Organisers said on Thursday that people from 80 countries were set to begin the march to Egypt's Rafah Crossing with Gaza.

Egypt's Foreign Ministry has said visits to the Rafah border region must be coordinated in advance with Egyptian embassies or government entities, and underlined the need to follow official procedures to ensure safety and security.

Organisers say they coordinated with Egyptian authorities and have urged the government to release those detained.

Groups of foreign participants were being held at checkpoints, and sit-ins had begun at two locations on the road leading to the Rafah crossing, organisers said.

They said police were stopping vehicles about 30 km (20 miles) from Ismailia, close to the Sinai peninsula, en route to Rafah, nearly 300 km away. Police were forcing passengers with non-Egyptian passports to disembark, they said.

Security sources confirmed that at least 88 individuals had been detained or deported from Cairo airport and other locations.

Officials at Cairo International Airport said new directives were issued to airlines requiring all passengers travelling to Egypt between June 12 and 16 to hold confirmed return tickets.

Three airport sources told Reuters on Thursday that at least 73 foreign nationals had been deported on a flight to Istanbul after authorities said they violated entry protocols, and that about 100 more were at the airport awaiting deportation.

Israel's defence minister told the Israeli military on Wednesday to prevent demonstrators from entering Gaza from Egypt, and said the march was a threat to Israeli and regional security.