Glenys Watson, who works at a cafe on the same road as the school, said the scene was "like a war zone".
"I've never seen so many police cars," she told the BBC.
More top news
Thirty facts about Prince Harry to celebrate his coming of age.
Django Unchained actress Danièle Watts was handcuffed by police after she was seen "showing affection" to her partner, NBC News reported.
A US news anchor has told viewers he only has four to six months to live on air, after he was informed that his brain tumour was inoperable.