Snakes from former Yugoslavia that are allegedly capable of crushing children to death are causing alarm in a plush part of central London.

A witness said that ex-fighter Marinko Bjelica, on trial for war crimes in Kalinovik, vowed to commit murder at a school where Bosniaks were detained, in order to avenge his two sons.

Around Gavrilo Princip’s home village in Bosnia, disputes over whether he was a hero or a terrorist have raised tensions ahead of the centenary of the outbreak of World War I.