Greta Thunberg and "Game of Thrones" actor Liam Cunningham are among 12 activists aboard the Madleen, which is operated by the Freedom Flotilla Coalition, that is on its way to Gaza.

Thunberg said she joined the Madleen crew to "challenge Israel's illegal siege and escalating war crimes" in Gaza and highlight the urgent need for humanitarian aid.

Israel won’t allow a flotilla of activists — including Swedish environmentalist Greta Thunberg — sailing toward the Gaza Strip to reach the coastal enclave, Defense Minister Israel Katz said on Sunday.