The UK's terror threat level has been raised from substantial to severe after two Jewish men were attacked in the northern London neighborhood of Golders Green on Wednesday . "Today, the national threat level has increased to 'severe,' which means a terrorist attack is considered highly likely," British Home Secretary Shabana Mahmood in a statement  on Thursday. "I know this will be a source of concern to many, particularly amongst our Jewish community, who have suffered so much," she added.