Now playing Next Next Series The geological clock of volcanoes The volcano is one of the most powerful representations of nature, it can change territories and subsequently the history of human kind. 27/03/2017
Now playing Next Belarus Minsk protesters arrested after calling for the release of colleagues Belarus police take protesters away for demanding the release of fellow activists who had been detained the day before 27/03/2017
Now playing Next United Kingdom Westminster attacker's motive may never be known - police It comes as the family of the police officer stabbed to death at the Houses of Parliament on Wednesday release a heartfelt statement 26/03/2017
Now playing Next United Kingdom Two remain in custody over Westminster attack Seven people arrested in raids related to Wednesday's attack have been released without charge. Two have been released on bail. 25/03/2017
Now playing Next United Kingdom London attack: police make further arrests and reveal suspect's birth name Nine are held in custody following the London attack. Police confirm the assailant was born Adrian Russell Elms. 24/03/2017
Now playing Next United Kingdom London attacker 'was a normal family man' The man who killed three people in an attack near Parliament in London has been named as Khalid Masood. 23/03/2017
Now playing Next World 'Public spaces' the modern terrorist targets Low-tech terrorist attacks expected to rise 23/03/2017
Now playing Next United Kingdom Theresa May tells MPs 'acts of normality' will defy terrorism The British prime minister has addressed the UK Parliament the morning after the terror attack on Westminster. 23/03/2017
Now playing Next United Kingdom UPDATE: London attacker identified as Khalid Masood, police Earlier police said they believed he 'acted alone'. 23/03/2017
Now playing Next United Kingdom Terrorists turn everyday objects into killing machines Brutal and simple everyday objects terrorists use to kill 23/03/2017
Now playing Next United Kingdom Third victim named as US citizen Kurt Cochran Cochran was in Europe with his wife Melissa to celebrate their 25th wedding anniversary, and had been due to return to the US on Thursday. 23/03/2017
Now playing Next United Kingdom Westminster attack: Second victim named as Aysha Frade One of the two people killed on Westminster Bridge Wednesday during the worst terror attack to hit London since 2005 was identified as Aysha Frade 23/03/2017
Now playing Next United Kingdom London terrorist "acted alone" as police arrest eight British police have made several arrests and raided addresses, including in Birmingham, in connection with the deadly London terror attack. 23/03/2017
Now playing Next United Kingdom Westminster horror described by eyewitnesses Wednesday’s bloodshed in Westminster marked the deadliest attack in London since suicide bombers killed 52 commuters on the city’s transport system in 2005. 23/03/2017
Now playing Next United Kingdom "Terror" dominates UK's front pages The violent events in London featured heavily on the front pages of the UK’s main newspapers the morning after the attack. 23/03/2017
Now playing Next United Kingdom Mayor urges Londoners and visitors not to be alarmed London Mayor Sadiq Khan adds his words of reassurance to Londoners and tourists after terror attack 23/03/2017
Now playing Next United Kingdom Westminster attack: The policeman who gave his life defending Parliament PC Keith Palmer, 48, of the Metropolitan Police's Parliamentary and Diplomatic Protection Command died of his wounds at Parliament 22/03/2017