Egyptian authorities have detained and questioned more than 200 people who arrived in Cairo to participate in the Global March to Gaza, an international action intended to break Israel’s siege on the territory, the organisers said on Thursday.

According to the march organisers, some 4000 people from over 40 countries had booked flights to Cairo, with many already arriving ahead of the planned march.

The activists had flown to Cairo to join a grassroots land convoy which set off from the Tunisian capital on Monday in the hopes of reaching Egypt’s Rafah border with Gaza as a “symbolic act” to spotlight Israel’s crippling 18-year siege on the territory.