Isis burn Jordanian hostage alive: What we do and do not know

A video published online by Isis militants on Tuesday shows Jordanian pilot Muath al-Kasaesbeh being burned alive. Authorities in Jordan now say they have executed two militants - one of them Sajida al-Rishawi, a female prisoner sought by Isis.

Here is what we know:

• The video shows a man believed to be al-Kasaesbeh in an orange jumpsuit standing upright in a cage.

• It is 20 minutes long and features the slick production and graphics used in previous videos released by the group.

• al-Kasaesbeh, 26, was captured by Isis (who sometimes call themselves the Islamic State) in December.

• Last week Jordan's government said it was willing to trade Sajida al-Rishawi, an al-Qaeda prisoner, for the pilot, but that it wanted proof of life first. But a scroll on Jordanian TV said that the pilot was killed on January 3. Jordan has now executed al-Rishawi and Ziad al-Karbouly, who has also been linked with al-Qaeda.

• The footage comes days after the murder of freelance journalist Kenji Goto by Isis.

• Reacting to the murder, David Cameron said it would "only strengthen our resolve to defeat Isis".

What we don't know

• When al-Kasaesbeh was killed.

• The uncertainty over the date al-Kasaesbeh was murdered raises questions over whether any of the hostage negotiations last week were sincere.

• Where the video was shot and by whom.

• The identity of the killers in the video and whether an Isis fighter with a British accent who became known in the media as 'Jihadi John' after previously featuring in such films, was one of them.

Additional reporting: AP

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