Threatens to use nuclear bomb in London

ISIS followers claim that they have assembled a dirty bomb from 40kg of uranium they found at Mosul University in July. One militant tweets about the impact the group anticipates if they were able to detonate it in London:

[..] terribly destructive

There is not further information on how ISIS would transport the weapon to the UK or if they have developed a viable bomb, however Iraq’s ambassador to the UN states that this could be considered the group having developed a weapon of mass destruction.