Israeli vessels are reported to have surrounded a ship carrying aid for Gaza. The Libyan organisation behind the operation says the Amalthea is still bound for the Palestinian territory.
Israel has offered the ship to land at its port of Ashdod and has warned it will not allow it to breach its naval blockade of Gaza.
Many are holding their breath, fearing a repeat of the bloody storming of a Turkish-flagged aid ship on May 31 in which Israeli marines killed nine pro-Palestinian activists.
The operation provoked a wave of international criticism and even the Israeli army has admitted mistakes were made.
An Arab lawmaker who took part in that flotilla has been stripped of some of her privileges in a rare move by the Israeli parliament.
In angry exchanges at the Knesset yesterday MPs accused Haneen Zoabi of being a traitor.
The vote means Israeli authorities can bar Zoabi from leaving the country and lift her right to a diplomatic passport.
Since the botched operation in May, Israel has eased its land restriction on goods entering the Gaza Strip but insists its naval blockade remains.