A man is in hospital after being attacked with a noxious substance.
Kent Police said the victim suffered burns to the back of his head, but his condition was not life threatening.
He was attacked at about 20:20 GMT on Sunday, as he walked into St Laurence Graveyard in Ramsgate, Kent, after walking along Manston Road.
Chf Insp Ian Swallow said: "Incidents like these are rare but we do not underestimate the impact it has on a community."
He added that there would be an increased police presence in the area as officers continued their inquiries.
No-one has been arrested in connection with the attack, and police have appealed for doorbell or dashcam footage to help with the investigation.