We've had no with boat for 19 hours, organisers saypublished at 20:54 British Summer Time 9 June
The Freedom Flotilla Coalition - which organised the boat's journey towards Gaza - says it's not been allowed with any of the 12 engers since the vessel was intercepted by Israel.
In a post on X, the group says it has not heard from them for 19 hours.
It adds that while Israel says the volunteers have not been harmed, they will be experiencing "the psychological impact of being forcibly abducted". The Israeli foreign minister said earlier that engers were "undergoing medical examinations to ensure they are in good health".
The coalition also thanks those "fighting for our team" and calls on ers to "keep the pressure up on states" to stop Israel’s "siege of Gaza".