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.

Climate activist Greta Thunberg has hit back at South Carolina Senator Lindsey Graham for mocking her Gaza trip, saying it spoke "a lot about their priorities".

As the activist set sail on an aid ship bound for Gaza, the senator posted online: "Hope Greta and her friends can swim!"