An explosive device thrown at officers investigating a robbery in Belfast could have caused in "mass murder", Northern Ireland police have said.
Three officers were hurt in the "indiscriminate and reckless" attack last night as they attended the reported robbery at a bookmakers on Shaw's Road in the west of the city, the force said.
One officer underwent surgery for severe arm injuries and remains in hospital for further surgery. The other two officers were admitted to hospital and released.
Chief Superintendent Alan Todd of the Northern Ireland police described it as "a clear attempt to murder officers" and said it could have killed many people walking outside shops nearby.
"This could have been a mass murder investigation this morning, not only of officers at the scene but indeed the members of that community who were going about their normal business on what is a shopping street," Todd told BBC Radio 4's Today programme.
"This was an indiscriminate and reckless attack aimed at killing police officers but with complete disregard to what might have happened to members of that community."
A man rode up on a bicycle and threw a pipe bomb on the ground. The shrapnel hit the officers and narrowly missed other people.
Todd said "We don't believe it is connected to the robbery at this stage, although it is early days in the inquiry and that can't be ruled out.