This is announced by the Israeli Ministry of Foreign Affairs in a statement.
"Israel will not allow ships to enter an active war zone and break what is a legal blockade", the statement reads, where it is also claimed that the terrorist-stamped Hamas has organized the sailing.
Instead, Israel urges the ships to dock at the Israeli Ashkelon, north of the Gaza Strip, and "unload the supplies there, from where they will be quickly and organized delivered to Gaza".
Israel has maintained a land, sea and air blockade of the Gaza Strip for many years. During the ongoing war, Israel has at times completely blocked emergency aid to the territory, which has contributed to the, according to the UN, fully developed famine that prevails in Gaza City and its surroundings.
The so-called Global Sumud Flotilla, where climate activist Greta Thunberg is one of hundreds of participants, has as a stated goal to break Israel's blockade and establish a humanitarian corridor to the war-torn area.
Two previous attempts by activists to reach Gaza by sea this summer were stopped by Israel.
