Three people were stabbed to death in a church in Nice in an attack French authorities have attributed to a Muslim extremist.
Video / AP
Britain raised its terror threat level to severe on Tuesday, its second-highest level, following recent attacks in Austria and France.
The threat level of severe means an attack in the United Kingdom is considered highly likely. The level had previously been at substantial, meaning an attack is thought to belikely.
The decision announced by Home Secretary Priti Patel came after a man who had previously tried to join the Islamic State group stormed through the center of the Austrian capital of Vienna armed with an automatic rifle and a fake explosive vest Monday night, killing four people before police shot and killed him.
Britain's Home Secretary Priti Patel announced the measures as precautionary. Photo / AP
Patel said the increased security alert is a "precautionary measure and is not based on any specific threat".
"The public should continue to remain vigilant and report any suspicious activity to the police," she said.
The UK government's Joint Terrorism Analysis Centre, which was established in June 2003, made the decision. The centre assesses intelligence relating to international terrorism, at home and overseas, and sets threat levels and issues warnings of threats and other terrorist-related information.
