On Wednesday afternoon, there was an attack outside Parliament in London.
Five people were killed in what police have described as a terrorist attack. Over 40 people were injured.
The area around the Houses of Parliament was closed off after the incident to keep people safe.
This is the most serious terrorist attack on London since the 7/7 bombings in 2005.
On Thursday morning, the UK prime minister, Theresa May, confirmed in parliament that the police have arrested eight people in relation to the incident.