A nesting swan suffered serious injuries after being attack with a catapult.
Hampshire Constabulary said the bird was nesting on an island at Swan Valley Lakes at Blackwater, near Farnborough, when it was attacked by two youngsters with a catapult at about 19:00 GMT on 15 April.
Molly Claydon from rescue charity Swan Lifeline said the attack was "horrifying".
Police have urged anyone with information or dashcam footage to get in touch.
Ms Clayton said the swan was covered in blood and very distressed when it was discovered and could not be caught to be treated.
"We tried to catch her, but she was too stressed. Luckily the eggs were only covered in her blood and not broken."
The swan's condition is being monitored and the area has been closed off in order to protect it.
She added: "Sadly, we are seeing swans attacked more and more.
"In the last year, these sort of attacks have really picked up. It's popular amongst the youngsters – they see it on social media and they want to show off to each other.
"It makes me really angry."
Danni Rogers, a volunteer with the Shepperton Swan Sanctuary, said he had also seen an increase in the number of attacks using catapults, describing it as "absolutely heartbreaking".
"It's getting worse, and something should be done about it," he added.