A warning has been issued to parents after groups of young children have disrupted nesting swans in Swindon.
Wiltshire Police said the birds at Shaftesbury Lake have been repeatedly harassed despite efforts to protect them.
The force are now asking people living in the Park North and Eldene areas for their help.
It comes after a report was made on Sunday 17 April that three children - two boys and one girl - were throwing stones at a swan as she sat on her nest. Police say the children were with a brown dog at the time of the incident.
Officers who attended later removed a one-metre-long pole from the nest, which had not previously been there.
Police Community Support Officers (PSCOs) are now conducting regular patrols by the lakes and have put measures in place to protect the swans.
But despite this, police say some harassment is still happening.
PSCO Edington said: "These attacks must stop and we are asking a parents to ensure that their children are not participating in them."
As well as the danger to the swans themselves, PSCO Edington said a swan is capable of breaking an adult human's leg with its wing - and they defend nests vigorously.
He said if offenders are identified "they will be dealt with robustly".
Anyone with information is being asked to call 101. If the attack is taking place at the time of the call, people should dial 999.