Terrorism is the use of indiscriminate violence to spread fear in a bid to achieve political, religious, ideological, or financial aims.
There have been various causes of terrorism in the UK. In the 20th Century, most attacks were linked to the Northern Ireland conflict. Since the 2000s, most terror attacks have been linked to Islamic extremism.
Since March 2017, security agencies and counter-terror policing have foiled 12 Islamist and four extreme rightwing plots. MI5 and police are running more than 500 live operations involving roughly 3,000 potential suspects at any one time.
In addition, they say there are more than 20,000 people who have previously been investigated and who could again pose a threat.
Since 1970, there have been at least 3,395 terrorist-related deaths in the UK, the highest in Western Europe. However, most of these happened within Northern Ireland, and since the Good Friday Agreement was signed in 1998, the numbers of deaths from terrorism has reduced markedly. Since 2001, there have been around 100 deaths from terrorism in Britain.
It is important to remember that the likelihood of you being caught up in a terrorist attack remains very small, but it’s still good to be vigilant.
Click here to find out more about some of the signs that terrorist activity may be being planned near you, and what to do about it.