Merseyside Police are conducting enquiries after a two-year-old girl suffered a head injury at a house in Walton yesterday (Tuesday 30 April).
A report was received just after 2pm that the girl had been struck with an arrow after a crossbow was discharged inside the property on Oakhouse Park.
The child was taken to hospital where her condition is described as serious.
Officers have seized the crossbow and it is being forensically examined.
Detective Inspector Sabi Kaur said: "I am sure the community in Walton will share our shock and distress at the fact a child could have been hurt in this way.
"Our enquiries into this incident are at a very early stage, and we are still trying to establish the full facts but we know it was an isolated incident."
DI Kaur added: "This incident shows the obvious dangers posed by firearms stored in Merseyside.
“We will continue to listen to all of the information we receive to help us identify and remove these weapons from the streets.
“You can provide information directly to police, or anonymously via Crimestoppers, which is completely independent of Merseyside Police."
Anyone with information about firearms is asked to contact Merseyside Police social media desk via Twitter @MerPolCC or Facebook Merseyside Police CC. You can also call 101 or contact the independent charity Crimestoppers anonymously, on 0800 555 111 or via their online form at: https://crimestoppers-uk.org/give-information/give-information.