A group of pro-Palestinian activists have launched another attempt to break the Israel naval blockade of Gaza. On Wednesday, two ships—one Canadian, one Irish—quietly left Turkey bound for Gaza. Known as the Freedom Waves to Gaza flotilla, the ships are hoping to reach Gaza by Friday, but Israel has threatened to stop the ships. Earlier this year, Greece blocked the departure of several ships from another flotilla heading to the region. In 2010, Israeli forces killed nine activists, including a U.S. citizen, on the “Mavi Marmara,” which was part of the first such international flotilla.