Developing…

Update:

According to BBC News, Gourdel, 55 years old, was seized on Sunday in the unsettled north-east Kabylie area of Algeria.

Islamic State militants warned on Sunday they would target Americans and other Western citizens, “especially the spiteful and filthy French”, after French jets joined the US in carrying out strikes in Iraq on IS targets.

Editor’s note: This post has been updated with additional tweets.