France and Ireland expressed serious concern Wednesday after Israeli naval forces intercepted the Global Sumud Flotilla en route to Gaza.

French Foreign Minister Jean-Noel Barrot urged Israel to ensure the safety of French nationals on board and facilitate their return, while Irish Foreign Minister Simon Harris described the interception of the humanitarian mission as “very concerning” and highlighted the flotilla’s role in drawing attention to Gaza’s humanitarian crisis.

The flotilla, carrying more than 50 ships with 532 civilian supporters from over 45 countries, set sail at the end of August loaded with humanitarian aid and medical supplies.

It was expected to reach Gaza’s coast on Thursday under normal circumstances, marking the first time in years that so many vessels have sailed together toward the enclave of 2.4 million Palestinians, which has been under an Israeli blockade for roughly 18 years.

Organizers reported that live broadcasts were cut off from most ships as Israeli forces blocked communications and moved to halt the convoy.