Please describe the attack. What did they look like?

Well one of them was very large, and the other rather skinny.

Not the boys, the Dementors.

Alright, right, well um, big. Cloaked. Then everything went cold, as though all the happiness had gone from the world.

Now look here, Dementors don't just wander into a muggle suburb and happen across a wizard, the odds are astronomical.

I don't think anyone would believe the Dementors were there by coincidence, Minister.

Ahem. I'm sure I must have misunderstood you, Professor. Dementors are after all under the control of the Ministry of Magic. So silly of me but it sounded, for a moment, as though you were suggesting that the Ministry had ordered the attack on this boy.

That would be disturbing indeed, madame Under-Secretary, which is why I'm sure the Ministry will be mounting a full-scale inquiry into why the two Dementors were so far away from Azkaban and why they mounted an attack without authorization. Of course, there is someone who might be behind the attack.