A fleet of about 50 vessels carrying humanitarian aid to Gaza resumed its voyage and was moving slowly southeast of Crete on Sunday, the ship-tracking platform MarineTraffic said.
The Global Sumud Flotilla (GSF) had to pause its journey over the past two days due to stormy winds and organizational issues. Weather conditions have now improved.
It remains unclear whether the Spanish deep-sea patrol boat Furor and the Italian frigate Fasan, dispatched by Madrid and Rome to the Eastern Mediterranean, have reached the flotilla.
Both ships are intended to assist if necessary, though how close they may approach the Israel-imposed blockade off Gaza is uncertain.
Israel has warned it may use force to prevent the flotilla from reaching Gaza's coastline. The country has proposed that the activists redirect the aid to the Israeli port of Ashdod, from where it could be transferred to Gaza under controlled conditions.
A Greek Cypriot port has also been discussed as an alternative staging point, with occasional aid shipments sent from there to Ashdod before reaching Gaza.
The flotilla organizers have rejected both options, insisting on delivering supplies directly to famine-hit Gaza.
The Global Sumud Flotilla set off from Barcelona in late August with hundreds of activists on board. "Sumud" means steadfastness in Arabic.
Last week, activists reported drone attacks on the fleet of ships, as well as flash grenades and disrupted radio communications.
Meanwhile, a flotilla of 10 vessels set off for Gaza from Sicily, southern Italy, on Saturday, with 60 people on board, including elected officials from nine nations, said organizers.
A statement from the Freedom Flotilla Coalition (FFC) and the Thousand Madleens to Gaza (TMTG) said they intended to "break the illegal Israeli blockade" to deliver aid to the Palestinian territory.
"For the most part, our boats carry medical supplies, dry food and school equipment, as this was highlighted as some of the biggest priorities by Palestinians on the ground," they added.
They intend to join the GSF, which is also bound for Gaza carrying aid supplies.
On board are elected officials from the European Parliament and from countries including Belgium, France, Ireland, Spain and the United States.
On Wednesday, the United Nations called for an investigation into alleged drone attacks off Greece against the Global Sumud Flotilla, which activists have blamed on Israel.
