Israel navy troops opened fire on pro-Palestinian activists aboard a six-ship aid flotilla sailing for the Gaza Strip, killing two of them and wounding 30 others, after the activists ignored Israeli orders to turn back.

The Israeli naval vessels reportedly made contact earlier with the six-ship flotilla, which is carrying 10,000 tons of humanitarian aid and supplies to Gaza.

The Israeli navy was operating under the assumption that the activists manning the boats would not heed their calls to turn around, and Israeli troops were prepared to board the ships and steer them away from the Gaza shores and toward the Israeli port city of Ashdod.

The flotilla, which includes three cargo ships and three passenger ships, is trying to draw attention to Israel’s three-year blockade of the Gaza Strip. The boats are carrying items that Israel bars from reaching Gaza, like cement and other building materials.

The activists said they also were carrying hundreds of electric-powered wheelchairs, prefabricated homes and water purifiers.

This is the ninth time that the Free Gaza movement has tried to ship in humanitarian aid to Gaza since August 2008.

Israel has let ships through five times, but has blocked them from entering Gaza waters since the three-week military offensive against Gaza's Hamas rulers in January 2009. The flotilla bound for Gaza is the largest to date, Haaretz reported.