Researchers at Newcastle University have released this footage of controlled explosions in London Underground carriages.
The first explosion shows a decommissioned carriage similar to that targeted by terrorists on the London Underground in 2005.
The second explosion is on a prototype carriage that has been redesigned by engineers to provide better protection for passengers.
More top news
The Trump administration is greatly expanding the number of illegal immigrants in the country who are considered a priority for deportation.
The feature on the Facebook-owned app is strikingly similar to similar "story" elements on Instagram and Snapchat.
Merseyside Police are hunting convicted murderer Shaun Walmsley after two armed men helped him escape custody while on a hospital visit.