“We are currently on scene near the swimming pool on Pinchbeck Road, Spalding, after receiving a report at 9am of a person injured,” a Lincolnshire Police spokesman said, adding “There is an ongoing police investigation and at this stage we are not looking for anyone else in connection with the incident.”
Those killed are believed to be two women and a man.
A force spokesman said there was no indication it was a “terror-related” incident.
BREAKING NEWS: Police and air ambulance at #Spalding’s Castle Sports Complex – https://t.co/7SQC0IiSbc pic.twitter.com/upcn5kyUu8
— Paul Fisher (@PaulFisheredit) July 19, 2016