This is in the article:
Teachers and police weren’t satisfied with Mohamed’s explanation that his invention was simply a clock.
>>>>>>>>>>>>>>>
Now they are satisfied? or not?
Everyone knows that teachers are often idiots, and neither teachers nor police are likely to be qualified to understand electronics.
In any case, it doesn't matter if it is a clock or a computer. If there are no explosives (and how would a kid obtain these?), it's not a bomb.