Ships carrying 10,000 tons of supplies and hundreds of pro-Palestinian activists to blockaded Gaza were being held up near Cyprus yesterday, as organisers tried to get nearly two dozen high-profile supporters on board.

The flotilla was to set sail toward Gaza yesterday afternoon, in any event, and approach the territory on Sunday, about 24 hours behind schedule, said Greta Berlin, one of the activists.

A showdown with the Israeli navy appeared inevitable. Israel's deputy foreign minister, Danny Ayalon, reiterated yesterday that the ships would be intercepted, denouncing the sea convoy as a provocation and violation of maritime laws. Israel and Egypt imposed a blockade on Gaza after the Islamic militant Hamas seized the territory by force three years ago.

In Gaza, prime minister Ismail Haniyeh of Hamas said the flotilla signals the end of the blockade.

"If the ships reach Gaza, it's a victory for Gaza," Haniyeh told some 400 supporters after touring Gaza City's small fishing harbour, where several smaller vessels breaking the blockade have docked in the past. "If they are intercepted and terrorised by the Zionists, it will be a victory for Gaza, too, and they will move again in new ships to break the siege of Gaza."

In Cyprus, organisers were trying to find a way to have two dozen would-be passengers, including 19 European legislators and an elderly Holocaust survivor, join the ships anchored in international waters off the island. The Cypriot government did not allow smaller boats to carry the group to the flotilla, Berlin said. Authorities in Cyprus said the decision was made to protect the island's "vital interests". Organisers then appealed to the Turkish government via the Turkish-controlled northern Cyprus port. Turkish Cypriot officials have said they want to help the group as much as they can.