Palestinian activists on Thursday condemned Israel for threatening to stop Irish and Canadian ships from breaking its naval blockade on the Gaza Strip. The two ships set sail Wednesday from a Turkish port, carrying 27 pro-Palestinian activists from nine countries and symbolic amounts of aid. \"The sailing of the two ships is the most significant response to the continuation of the maritime closure,\" said Amjad Al-Shawa of the Gaza-based Palestinian Network of NGOs. The vessels are expected to enter Gaza waters Friday morning, but Israel Radio quoted unidentified sources as saying that the Israeli navy will block the voyage and prevent the ships from reaching the Hamas-controlled Gaza Strip. Rami Abdu, a Palestinian activist who takes part in organizing Gaza-bound flotillas, said in a statement that the activists will send more ships from Turkish and Greek ports. In May 2010, Israeli commandos blocked a Turkish-led flotilla from reaching Gaza and killed eight Turkish nationals and a U.S. citizen of Turkish descent during the operation to take over the ship. The incident caused severe tension in the Israeli-Turkish relations and forced Israel to ease the overland closure on the Gaza Strip, while the naval blockade remained intact.