Police press conference going on now.
Eleven transported to hospital- five were LEO.
Police keeping firm control of media, warning them not to try to talk over each other but to wait and ask their questions one at a time. Police spokeswoman answering only what is absolutely known, not speculating. Says it will be days before all the evidence is analysed. No name or motive released, and spokeswoman again refusing to speculate. Good for her!