An aid ship set sail on Monday towards the Gaza Strip in a new attempt to break Israel's two-year-old blockade on the Palestinian territory, officials said.

The Gaza-based international campaign against the siege said that 21 European activists were aboard, sailing to the Hamas-controlled territory from the Mediterranean port city of Larnaca in Cyprus.

The campaigners began the voyage after one-week delay which the Cyprus authorities attribute to safety tests and examinations the small fishing boat needs to go through. The organizers believe the delay was a result of Israeli pressures.

The ship, which also carry symbolic amounts of medical supplies, is expected to complete its 30-hour trip and dock at Gaza's port Tuesday noon if the Israeli navy doesn't turn it back.

Before Israel launched its three-week major military offensive in Gaza in late December, six ferries succeeded to make their way to the besieged enclave in five voyages.

After the end of the war, the Israeli gunboats intercepted a similar trip and forced it back to the international waters.

Israel sealed off Gaza in June 2007, citing Islamic Hamas movement's takeover of the territory.

(Xinhua News Agency June 30, 2009)