Armed officers from the Met Police Trojan unit have been called to an incident in Orpington in Kent.
A man was struck in the leg by what is claim to have been an airgun.
A spokesman for the Met Police said: Officers were called at approximately 1.50pm on Sunday, 23 August after a man reported being struck in the leg with an object near Crockenhill Road, Orpington. The object had been fired from nearby woodland.
Other items were also reportedly fired or thrown from the woodland.
Officers attended but no suspects could be located.
The man was assessed by a paramedic at the scene but did not go to hospital.