A "mass fight" which broke out at a holiday park in Devon reportedly forced people to leave the site on Christmas Day.
Police received reports of the serious incident at Welcome Family Holiday Park in Dawlish Warren overnight on Christmas Eve.
There were local reports that armed police, dog units and a police helicopter were all dispatched.
A spokesperson for Devon and Cornwall Police said: "There was significant disorder at the Welcome Family Holiday Park in Dawlish Warren during the early hours of December 25.
"Police are investigating a GBS [Grievous Bodily Harm] related to the disturbance. Police presence in the area will remain highly visible for the next 24 hours to respond to community concerns."
Neighbours were reportedly left "shocked" and "appalled" by the events.
One witness said: "I noticed trouble brewing on Christmas Eve when I walked to the local shop where the store assistant said lads had been in and out stealing. They were very intimidating.
"Unusually, I saw three police cars circling the area - this was about 4pm. You don’t normally see any police cars here. This time of year the place is usually very quiet.
"I had a feeling things might escalate. What a pity events turned to violence and innocent family holidaymakers have now had their Christmas ruined."
Another neighbour said: "I live next door to the Welcome Park, and those screams were blood-curdling last night.
"It is not an infrequent event, as there were police on the park due to a separate incident the previous night.
"They have ruined my children's Christmas who were unable to sleep due to police and helicopters being present on scene.
"I didn't get to sleep until 4am, having been woken up by the horrifying screams of guests."
ITV West Country has contacted Welcome Family Holiday Park for a comment.