The film, which is adapted from Rebecca Skloot's 2010 book of the same name, chronicles Deborah's search to learn about the mother she never knew.

Police said they had arrested two men, aged 28 and 31, originally from Kosovo, and were trying to establish how advanced the plot was.

Trump said "the U.S. must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes."

The 19-minute video was posted on jihadist websites and was supposedly shot in the IS-declared "Aleppo Province" in northern Syria.