"The public should be clear about what this means. A threat level of severe means an attack is highly likely,” she said. “The country should remain vigilant."
The threat assessment has returned to the level it was at prior to the Manchester attack.
In Manchester, events planned around the spring bank holiday will go ahead with additional security, including a significant number of armed officers, police said. British officers do not usually carry guns, CNN reported.
Events include the Manchester Games, the Great Manchester Run, and a stadium show by bands including The Courteeners, all of which are likely to attract big crowds. This weekend also marks the start of Ramadan, the holiest month of the Muslim calendar, CNN reported.